The Complete Guide to Metal Materials and Sizes

Most metal sizing references are either vendor-specific catalogs, single-material guides, or imperial-only tables that leave you hunting for a conversion. This post collects every common form — sheet, plate, pipe, tube, HSS, angle, channel, beam, and bar stock — into one place, with consistent notation, both imperial and metric dimensions, and cross-section diagrams you can actually use to understand what you're ordering.

It's aimed at designers, fabricators, welders, students, and buyers who need a reliable reference without wading through a 1,400-page AISC manual. The data comes directly from ASME B36.10M (pipe), AISC Steel Construction Manual (structural shapes), ASTM standards (plate and sheet), and Manufacturer's Standard Gauge tables — not from vendor spec sheets, which vary.

A note on scope: Can-Cut runs a CNC plasma table that cuts flat plate up to 3/4" steel and 1/2" aluminum or stainless. Pipe, tube, structural shapes, and bar stock are included here as reference material — we don't cut them on the plasma table. Knowing the full material catalog still matters when you're designing a fabricated assembly; you need to know what raw stock is available before you can specify the parts you want cut.

Table of Contents

• Section 1 — How metal sizes are described
• Section 2 — Sheet metal and gauge
• Section 3 — Plate
• Section 4 — Round tube and pipe
• Section 5 — Square and rectangular HSS
• Section 6 — Angle iron
• Section 7 — C-channel
• Section 8 — I-beams and W-shapes
• Section 9 — Bar stock
• Section 10 — Specialty metals
• Section 11 — Choosing the right form
• Section 12 — What Can-Cut cuts

Section 1 — How metal sizes are described

Inch fractions, decimals, and metric

North American metal stock is sold almost entirely in inch fractions: 1/4", 3/8", 1/2". Drawings and machining specs often need decimal equivalents (0.250", 0.375", 0.500"). Metric equivalents (6.35 mm, 9.53 mm, 12.70 mm) matter when you're sourcing material internationally or working to ISO drawings. A reliable conversion is just multiplication by 25.4 for inches-to-mm, or division by 25.4 for the reverse. Do not round metric conversions at the input — carry four decimal places through calculations and round the final result to two.

Gauge and why it's confusing

Gauge is the oldest metal-thickness system and the most confusing. The problem: there is no single gauge system. Carbon steel sheet uses Manufacturer's Standard Gauge (MSG). Galvanized steel uses a slightly different table because the zinc coating adds thickness. Stainless steel uses its own gauge table. Aluminum uses the Brown and Sharpe (B&S) system, which is also called American Wire Gauge (AWG) for round wire.

The numbers run backward — higher gauge number means thinner material. 30 gauge is about 0.012" thick; 7 gauge is about 0.179". This made more sense historically when gauge referred to the number of draws required to produce the wire, but it's an inherited quirk that causes real confusion when someone orders "16 gauge stainless" expecting carbon steel thickness.

The rule: always confirm which gauge table applies to your material before ordering or designing.

Nominal vs actual

Many structural shapes are sold with nominal dimensions that don't match actual dimensions. NPS (Nominal Pipe Size) is the most extreme example: NPS 2 pipe has a real outside diameter of 2.375", not 2". Nominal pipe size was standardized in the 1800s and was never updated when manufacturing tolerances improved.

W-shape beams have nominal depth labels that approximate but don't match actual depth. A W6 × 9 has actual depth 5.90", not 6.00". The nominal depth is a "roll group" label — several different W6 shapes share the same rolling geometry but differ in flange and web thickness.

HSS (Hollow Structural Sections) and bar stock are sold to actual dimensions — what you specify is what you get, within mill tolerance.

Why structural shapes have weight in their names

W-shapes, channels, and angles carry their weight per foot as part of the designation. A W12 × 26 is a wide-flange beam with 12" nominal depth and 26 lb per linear foot. This is useful: it lets you compute total weight from length alone, and it distinguishes shapes within the same depth group. A W12 × 14 and a W12 × 26 have nearly the same depth but significantly different cross-sections.

Quick conversion tips

• 1" = 25.4 mm exactly
• 1 lb/ft = 1.488 kg/m
• Gauge to decimal: use the tables in Section 2 — do not guess
• Fractions to decimal: divide numerator by denominator (3/8 = 0.375)

Section 2 — Sheet metal and gauge

Sheet metal is the raw material for enclosures, brackets, guards, covers, panels, and thousands of other formed parts. It's defined by thickness (gauge or decimal) and sold in standard sheet sizes, most commonly 36" × 96", 48" × 96", 48" × 120", and 60" × 120".

Manufacturer's Standard Gauge — carbon steel

The MSG table governs hot-rolled and cold-rolled carbon steel sheet. It's used for mild steel (A36, A1011, A1008). The gauge numbers you'll encounter most often in fabrication are 18 gauge (0.0478" / 1.21 mm) through 11 gauge (0.1196" / 3.04 mm). Anything above 10 gauge starts to overlap with what mills call "plate" and is often sold by fraction rather than gauge number.

Galvanized steel gauge

Galvanized sheet uses a separate table because the hot-dip zinc coating adds approximately 0.003" per side. A 20 gauge galvanized sheet (0.0396") is measurably thicker than a 20 gauge bare carbon steel sheet (0.0359"). The difference matters in tight-clearance assemblies. When punching or plasma cutting galvanized sheet, be aware of zinc fume generation — proper ventilation is required.

Stainless steel gauge

Stainless sheet gauge doesn't match MSG. 20 gauge stainless is 0.0375", while 20 gauge carbon steel is 0.0359" — close but not identical. Some gauges (11 gauge and 7 gauge) aren't standardized for stainless at all. 304 and 316 stainless are the two most common grades for sheet and plate; 304 is the general-purpose choice, 316 adds molybdenum for better chloride resistance.

Brown and Sharpe / AWG — aluminum

Aluminum uses an entirely different gauge system, the Brown and Sharpe gauge (B&S), which is the same as American Wire Gauge (AWG). The numbers don't line up with steel at all: 16 B&S aluminum is 0.0508", while 16 MSG steel is 0.0598". For structural aluminum sheet work, many buyers skip gauge entirely and specify decimal thickness or a fraction: "0.080" aluminum" or "1/8" aluminum" is unambiguous.

Full gauge comparison table

The following table shows all four materials side by side. Values in inches; mm in parentheses. "—" means that gauge is not standardized for that material.

Common applications by gauge range

30–24 gauge (0.012"–0.024"): Ductwork, HVAC components, electronics enclosures, thin formed parts. Requires a brake or roll former; cuts easily with shears or laser.

22–18 gauge (0.030"–0.048"): The fabrication sweet spot. Most sheet metal brackets, enclosures, guards, and covers fall here. Weldable, formable, plasma-cuttable. 18 gauge is the typical floor for structural brackets.

16–14 gauge (0.060"–0.075"): Heavier brackets, structural panels, trailer floors, agricultural equipment. Gets into plasma-cutting territory for most shops.

12–10 gauge (0.105"–0.135"): Approaching plate thickness. Often referred to as "heavy sheet" or "light plate" depending on the mill. Plasma cutting works well here.

When to order sheet vs plate

Use sheet when you need to form, bend, or roll the material. Use plate when the part is flat, load-bearing, or needs to be cut to a near-net shape. The 3/16" threshold is a practical boundary: below it, most mills produce and sell the material as "sheet" on a shear; at and above it, the material is typically cut to order from plate stock.

Section 3 — Plate

Plate is the foundation of plasma cutting work. Flat parts — flanges, gussets, brackets, frames, wear plates, stiffeners — are all cut from plate. The industry convention is that plate starts at 3/16" (4.76 mm), though some mills use 1/4" as the threshold. Below that is sheet.

Standard plate thicknesses

These are the standard fractions available from North American steel service centers. Custom thicknesses exist but carry long lead times and minimum order quantities.

Standard plate sheet sizes

Plate comes in standard mill sizes. The most common:

• 48" × 96" (4 × 8 ft) — most common, fits in most shops
• 48" × 120" (4 × 10 ft) — common for longer parts
• 60" × 120" (5 × 10 ft) — common for wider parts
• 72" × 240" (6 × 20 ft) — heavy structural

Longer and wider plates are available as mill-direct orders but are less common at service centers.

ASTM grades

A36 is the default mild steel plate for most fabrication. Yield strength 36 ksi, tensile 58–80 ksi. Weldable with standard processes. If a drawing says "steel plate" without a grade, A36 is almost always what's intended.

A572 Grade 50 is high-strength low-alloy (HSLA) steel with 50 ksi yield. Used when you need more strength at less weight — trailer frames, crane booms, equipment frames. Slightly more expensive than A36; also weldable.

A516 Grade 70 is a pressure vessel steel with controlled chemistry for low-temperature toughness. 70 ksi tensile. Used for tanks, pressure vessels, boilers. Not for general structural fab.

AR400 / AR500 are abrasion-resistant steels (400 and 500 Brinell hardness, respectively). Used for bucket liners, chutes, wear plates, dozer blades. Not weldable with standard wire — requires preheat and low-hydrogen consumables.

Thickness tolerance

ASTM A6 covers thickness tolerances for structural plate. For 3/16" to 1/4" plate: mill tolerance is +0.030" / -0.000" (underthickness not permitted). For heavier plate the percentage tolerance tightens. In practice, most plasma-cut parts are toleranced ±0.015" on overall dimensions, which far exceeds what the plate mill tolerance contributes.

What Can-Cut stocks

Can-Cut's plasma table handles plate from 18 gauge through 3/4" in mild steel (A36), stainless 304 and 316, and aluminum 5052 and 6061. If you need a part cut from a specific grade like A572-50 or AR400, ask — supply availability varies by thickness and timing.

Section 4 — Round tube and pipe

Round hollow sections come in two fundamentally different sizing systems: pipe (sized by NPS and schedule) and tube (sized by actual OD and wall thickness). They're not interchangeable and are used for different applications.

Pipe: NPS and schedule

Pipe is governed by ASME B36.10M (carbon and alloy steel) and B36.19M (stainless steel). The key concepts:

NPS (Nominal Pipe Size) is a historical label, not a measurement. For NPS 1/2 through NPS 12, the NPS number is neither the OD nor the ID. The OD is fixed for each NPS — it doesn't change as you change schedules. At NPS 14 and above, NPS equals OD in inches.

Schedule controls wall thickness. Heavier schedule = thicker wall = smaller bore. Common schedules:

• Sch 5 — very light, thin-wall, used for low-pressure lines
• Sch 10 — light wall
• Sch 40 / STD (Standard) — the default for most piping
• Sch 80 / XS (Extra Strong) — heavy wall, high pressure
• Sch 160 — very heavy
• XXS (Double Extra Strong) — heaviest standard wall; not available at all NPS sizes

NPS dimensions table

All wall thicknesses in inches. OD is fixed for each NPS regardless of schedule. "—" means that schedule is not standardized at that NPS.

Tube: actual OD and wall

Mechanical tube is sized by its actual outside diameter and wall thickness. A "2.000" OD × 0.083" wall" tube has exactly those dimensions — no nominal offset, no schedule lookup. This makes tube more intuitive to design with, which is why it dominates structural and mechanical applications where you need a specific geometry rather than a flow capacity.

Tube types differ by manufacturing process:

DOM (Drawn Over Mandrel): Cold-drawn after welding, producing tight OD and ID tolerances and a smooth internal surface. Used for hydraulic cylinders, precision mechanical components, and applications where roundness matters.

ERW (Electric Resistance Welded): Formed from strip and seam-welded. Economical, adequate for most structural and machine-frame applications. The weld seam is visible internally but not a weak point under most loading.

Seamless: Extruded without a weld seam. Higher cost; specified for high-pressure hydraulics, critical pressure vessels, and applications where any weld inclusion is unacceptable.

Mechanical tube: A general term for non-pressure round tube used in frames, guards, and machine components. Usually ERW.

Structural tube (HSS): Square, rectangular, or round hollow sections per ASTM A500/A1085. Covered in Section 5.

Common round tube OD sizes (mechanical, inches): 1/2, 5/8, 3/4, 7/8, 1, 1-1/4, 1-1/2, 1-3/4, 2, 2-1/2, 3, 3-1/2, 4, 5, 6. Walls range from 0.035" (thin) to 0.500" (heavy). The most common wall for light structural tube is 0.083"–0.120".

When to choose pipe vs tube

Use pipe when the application involves fluid or gas conveyance and you need to interface with standard pipe fittings (threaded, flanged, or grooved). The NPS system exists because fittings are made to specific NPS ODs — a fitting for NPS 2 fits NPS 2 pipe, period.

Use tube when the application is structural, mechanical, or decorative and you need a specific geometry that can be welded, bent, or machined. Tube gives you the actual size you specify. If someone asks for "2-inch round tube," clarify: do they mean 2.000" OD tube or NPS 2 pipe (2.375" OD)? They're different objects.

Section 5 — Square and rectangular HSS

HSS (Hollow Structural Sections) are the square and rectangular tubes used in structural fabrication — columns, beams, trailer frames, gates, railings, and machine bases. They're sized by actual outer dimensions and wall thickness, so unlike pipe, there's no nominal-vs-actual confusion.

Standards

ASTM A500 Grade B is the most common North American HSS for structural applications. Fy = 46 ksi, Fu = 58 ksi.

ASTM A500 Grade C has slightly higher minimum yield (Fy = 50 ksi) and is increasingly specified in structural engineering for weight savings.

ASTM A1085 is a newer standard with tighter dimensional tolerances and a minimum Fy of 50 ksi. The key improvement is the limit on wall thickness under-tolerance (10% in A500 vs 3.5% in A1085), which matters when calculating section properties for structural design.

Notation

HSS [outer dim] × [outer dim] × [wall thickness]

For square: HSS 4 × 4 × 1/4 — 4" per side, 1/4" wall. For rectangular: HSS 6 × 3 × 3/16 — 6" long side × 3" short side × 3/16" wall. The larger dimension is always listed first per AISC convention.

Square HSS — available sizes and walls

Rectangular HSS — available sizes and walls

Wall thickness selection rules of thumb

1/8" (0.125"): Light gates, handrails, decorative frames. Adequate for small spans with minimal load.

3/16" (0.1875"): Light trailer tongue boxes, interior supports, medium gates. Common entry point for structural applications.

1/4" (0.250"): Trailer frames, equipment frames, moderate structural columns. The most common wall for structural HSS.

3/8" and above: Heavy structural columns, high-load supports, seismic bracing. At 3/8" wall, section weight increases substantially — verify that the added weight is justified by the loading.

Section 6 — Angle iron

Angle iron (technically called an "angle" in AISC notation) is an L-shaped section used for bracing, brackets, frame members, edge protection, and trailer tongues. It's one of the most versatile structural shapes in light fabrication.

Equal-leg vs unequal-leg

Equal-leg angles have matching leg lengths (2" × 2", 4" × 4"). Unequal-leg angles have different leg lengths (4" × 3", 6" × 4"). Unequal-leg angles are specified longer-leg-first by AISC convention — L 4 × 3 × 3/8 means a 4" leg, a 3" leg, and 3/8" thickness.

Notation

L [leg A] × [leg B] × [thickness] or simply [leg A] × [leg B] × [thickness]. For equal-leg, leg A = leg B.

Equal-leg angle table

Weights from AISC Steel Construction Manual (14th edition). ASTM A36.

Applications

Small angles (1" through 2") are common for bracket gussets, shelf supports, and light framing. Medium angles (2-1/2" through 4") are workhorses for trailer frames, equipment skid rails, and agricultural equipment. Large angles (5" and above) appear in structural building frames and heavy machinery bases. For plasma-cut brackets and gussets, you're cutting from plate — but understanding angle stock sizes helps when you're designing an assembly that will include both cut parts and purchased structural steel.

Section 7 — C-channel

C-channel (C-shape, standard channel) is an open section with a web and two flanges. It's efficient in bending when oriented so the flanges carry the tension and compression, and it's commonly used for light structural members, conveyor rails, shelf supports, door frames, and vehicle frames.

C-channel vs MC-channel

Standard C-channel has a tapered inside flange — the flange is thicker at the web and thinner at the tip, with approximately 16° taper. This matches standard pipe and structural bolts for easy assembly, but makes welding fillet welds to the inside face slightly awkward.

MC-channel (miscellaneous channel) has parallel flanges — no taper. It's used when a flat contact surface is needed. MC-channel sizes overlap with C-channel but are designated differently (MC6 × 12.0, etc.).

Bar channel (sometimes called "structural channel") is a smaller form sold by leg length and thickness rather than depth and weight.

Notation

C[depth] × [weight per foot]. A C8 × 11.5 is 8" deep and weighs 11.5 lb per foot. Within a given depth group, heavier weight means thicker web and wider flange.

Standard C-channel table

All data from AISC Steel Construction Manual. Depths from 3" through 15".

Applications

C-channel shows up in building frames (purlins, girts), machinery beds, vehicle sub-frames, conveyor tracks, dock bumpers, and any application where you need a structural member that can be attached with a flat back face. For plasma cutting: gusset plates and bracket plates that interface with channel are common; the connection plate dimensions need to account for the flange taper on standard C-channel.

Section 8 — I-beams and W-shapes

S-shape vs W-shape

The old American Standard I-beam (S-shape) has relatively narrow flanges that taper significantly toward the tips. S-shapes are still produced and used, particularly in crane runway beams where the tapered flange mates with standard crane hoist hooks. For most structural applications, the W-shape has replaced S-shape because wider, parallel flanges distribute bending stress more efficiently and bolt more easily.

The W-shape (wide flange) is the default structural beam in North American construction. Flanges are nearly parallel (small taper, typically 1:20 or less). The wider flange relative to depth gives W-shapes a higher moment of inertia per unit weight than S-shapes at the same depth.

Notation

W[nominal depth] × [weight per foot]. The nominal depth is the label for the roll family — actual depth varies slightly within the same depth group as different section weights share the same rolling mill but use different pass thickness. A W18 × 35 has actual depth 17.70", not exactly 18.00".

Standard W-shape table

All data from AISC Steel Construction Manual. Actual depths are given, not nominal.

Applications

W-shapes are the backbone of steel building construction — floor beams, roof beams, columns, and crane runway girders. In heavy fabrication they appear as machine frames, press frames, and equipment supports. W-shapes with wide flanges (W6 × 15 to W14 × 43, where flange width approaches depth) are used as columns because they resist bending in both axes efficiently.

A brief taxonomy of related shapes: HP-shapes (bearing piles) look like W-shapes but have equal flange and web thickness for driving; M-shapes are miscellaneous shapes that don't fit W or S categories; built-up sections are fabricated from plate and weld to create custom I-shapes when no standard section provides the required section modulus.

Section 9 — Bar stock

Bar stock is solid metal in standard cross-sections: flat, square, round, and hexagonal. It's the raw material for machined parts, weld-on tabs, handles, pins, shafts, and structural connectors.

Flat bar

Flat bar is specified as thickness × width: "1/4 × 2 flat bar" is 1/4" thick and 2" wide. This is different from plate — flat bar is narrow enough to roll-mill directly; plate is wide stock cut to width. The distinction matters for straightness tolerance and surface condition (bar stock typically has better straightness than plate strips).

Common thicknesses: 1/8", 3/16", 1/4", 5/16", 3/8", 1/2", 5/8", 3/4", 1", 1-1/4", 1-1/2", 2"

Common widths: 1/2", 5/8", 3/4", 1", 1-1/4", 1-1/2", 2", 2-1/2", 3", 4", 5", 6", 8", 10", 12"

Not every thickness/width combination is stocked — narrower bars have fewer available thicknesses. A service center stocks the common pairings; anything unusual may be a cut-to-size order from wider plate.

Round bar

Round bar is specified by diameter. The full range from 1/8" through 6" is available from most steel service centers; larger diameters are specialty items. Round bar for machining shafts and pins is typically 1018 or 1045 cold-rolled steel; for heat-treated applications, 4140 or 4340 alloy steel.

Common diameters: 1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-1/2", 1-3/4", 2", 2-1/2", 3", 4", 5", 6"

Square bar

Square bar is specified by side dimension. Sizes from 1/4" through 3" are common stock.

Common sizes: 1/4", 5/16", 3/8", 1/2", 5/8", 3/4", 7/8", 1", 1-1/4", 1-1/2", 2", 3"

Hex bar

Hex bar is specified across flats (AF) — the distance between two parallel flat faces, which is what a wrench engages. Do not confuse across-flats with across-corners; the AF dimension is the one that determines wrench size.

Common AF sizes: 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 3/4", 7/8", 1", 1-1/4", 1-1/2", 2"

Material grades for bar stock

1018 cold-rolled steel: The general-purpose machining bar. Good surface finish, tight tolerances, low carbon. Suitable for turning, milling, drilling. Not great for heat treatment due to low hardenability.

1045: Medium-carbon steel with better strength and wear resistance than 1018. Used for axles, shafts, gears, and other moderate-duty mechanical parts.

4140 chromoly: Low-alloy steel with excellent strength, toughness, and hardenability. The standard for structural shafting, tooling, and any application that needs heat treatment to RC 30–50.

1144 Stressproof: A resulfurized, rephosphorized free-machining steel with high strength and good machinability from the bar without heat treatment. Popular for precision turned parts.

12L14: Lead-bearing free-machining steel — best machinability of any common bar stock. Used for high-volume turned parts on CNC lathes. Not weldable; avoid where welding or cold forming is needed.

Mill lengths

Bar stock is typically sold in:

• 12 ft random lengths (may vary 11–13 ft depending on the mill run)
• 20 ft random lengths for larger sizes
• Cut-to-length at a service center surcharge
• 8 ft lengths are sometimes available but less common

If you're designing parts that will be cut from bar, design to minimize offcuts from 12-ft lengths.

Section 10 — Specialty metals

Plasma cutting works only on electrically conductive metals. The plasma arc requires the workpiece to complete the circuit, which eliminates non-conductive materials entirely and makes some metals impractical to plasma-cut due to their thermal or chemical properties. This section covers the most common specialty metals and notes where plasma cutting applies.

Brass

360 free-machining brass (CDA 360) is the most widely used brass alloy — excellent machinability, good corrosion resistance, used for fittings, valves, fasteners, and decorative hardware. 260 cartridge brass is softer and more formable, used for shell casings, heat exchanger fins, and sheet metal forming. 385 architectural brass is used for trim, railings, and hardware where appearance matters.

Brass is conductive, so plasma cutting is technically possible, but the low melting point and tendency to produce zinc fumes make laser or waterjet the preferred process for most brass work. Plasma-cut edges on brass are rough and prone to dross.

Copper

C110 ETP (Electrolytic Tough Pitch) is the standard commercial copper, used for electrical bus bar, heat exchangers, and roofing. C101 OFHC (Oxygen-Free High Conductivity) is used where hydrogen embrittlement would be a concern (vacuum furnace components, high-frequency electronics).

Copper is plasma-cuttable but highly thermally conductive, which makes it difficult — the heat dissipates before the kerf melts cleanly. Laser and waterjet are better choices for copper plate work.

Bronze

Bronze alloys are used primarily in bearing and wear applications. C932 bearing bronze (leaded tin bronze) is the standard for bushings and thrust washers. C544 phosphor bronze has good spring properties and fatigue resistance, used for electrical contacts and springs.

Bronze is plasma-cuttable but similar considerations to copper apply. For bearing applications, the stock is machined to final dimensions from bar or bushing stock rather than cut from plate.

Titanium

Grade 2 (commercially pure titanium) has excellent corrosion resistance, used in chemical processing and marine applications. Grade 5 (Ti-6Al-4V) is the aerospace workhorse — high strength-to-weight ratio, heat-treatable, used for aircraft structure, fasteners, and implants.

Titanium can be plasma-cut, but it requires argon shielding gas rather than air to prevent contamination of the cut edge. Plasma-cut titanium with an air torch produces an oxidized, contaminated surface unsuitable for welding or structural use without post-processing. This is a specialized process.

Lead

Lead is used for radiation shielding (medical X-ray rooms, nuclear applications), ballast, and sound deadening. Soft, dense, and not weldable by conventional processes. Not plasma-cuttable in any meaningful sense — it melts at 621°F (327°C) and vaporizes, generating toxic fumes. Laser cutting is sometimes used with appropriate fume extraction.

Zinc

Zinc is used primarily in hot-dip galvanizing baths (protecting steel) and as sacrificial anodes (protecting submerged steel structures from galvanic corrosion). In sheet form it's used for die casting and some architectural applications. Not typically plasma-cut.

Magnesium

Magnesium alloys (AZ31, AZ61) are extremely light — about 35% lighter than aluminum by volume. Used in aerospace and automotive for weight-critical structural parts and housings. The critical safety note: magnesium chips and dust are highly flammable and can ignite spontaneously. Machining magnesium requires dry cutting, no water-based coolants, and fire suppression on hand. Plasma cutting is not recommended — the spark-heavy process and magnesium's flammability are an obvious combination to avoid.

Section 11 — Choosing the right form

A quick decision guide for common fabrication scenarios:

Need a flat 2D shape with holes, slots, or a custom profile? Plate or sheet — this is the plasma cutting use case. If it's a flat part with a complex outline, you want flat stock cut to shape. Thickness range and material drive whether it's sheet (gauge) or plate (fraction). See how plasma cutting works for the process behind this.

Need a long straight structural member that carries axial or bending load? HSS (columns, frames, gates), W-shape (beams, columns in buildings), C-channel (purlins, frame rails), or angle iron (bracing, light frame), depending on the section modulus you need and which axis the load is applied to. For a column carrying axial compression, HSS and wide-flange W-shapes both work — HSS handles biaxial bending equally, W-shapes are more efficient if bending is primarily in one axis.

Need to convey fluid or gas? Pipe — sized by NPS and schedule. Match the schedule to the pressure rating. If you're connecting to standard fittings, you must use pipe, not tube — the OD must match the NPS standard for threaded or flanged connections to work.

Need a tube for structural support (column, rail, guard)? HSS or mechanical tube, depending on whether the section needs to match AISC section properties. HSS is per ASTM A500/A1085 and has defined section properties in the AISC manual. Mechanical tube (ERW, DOM) is sized to actual OD and wall and doesn't have AISC section property tables, so you'd need to calculate properties yourself.

Need a stiff beam resisting bending? W-shape or HSS rectangular, depending on depth available and biaxiality of loading. W-shapes are more efficient in strong-axis bending for a given weight because the flanges are farther from the neutral axis.

Need a small structural connector, gusset, or clip angle? Angle iron in the appropriate leg size and thickness. For plasma-cut gussets from plate, see how to prepare a DXF file.

Need a turning blank for the lathe? Round bar in the appropriate diameter and material. For general machine work, 1018 is the default; for shafts under load, 1045 or 4140.

Need milling stock for a machined part? Flat bar or square bar. Flat bar gives you two finished surfaces to reference; square bar is the starting point for symmetric parts. Size up slightly from the finished dimensions to leave machining stock on all faces.

Need a precision shaft or pin? Round bar (1045, 1144, or 4140 depending on strength and machinability requirements), or cold-finished round bar for better dimensional tolerance and surface finish than hot-rolled.

Section 12 — What Can-Cut cuts

Can-Cut operates a 48" × 96" CNC plasma table, which handles flat plate and sheet from 18 gauge through 3/4" thick. We keep the following materials in stock:

• Mild steel (A36): 18 gauge through 3/4" plate
• Stainless 304: 18 gauge through 1/2" plate
• Stainless 316: 18 gauge through 1/2" plate
• Aluminum 5052: 18 gauge through 1/2" plate
• Aluminum 6061: 18 gauge through 1/2" plate

The process: you upload a DXF file, get an instant online quote, pay, and we ship to you anywhere in Canada. There's no minimum quantity — one part is fine. Tolerances are typically ±0.030" on cut dimensions for steel at standard feeds, tighter for thinner material. For a complete discussion of what to expect, see plasma cutting tolerances.

Parts that fall outside the 48" × 96" cutting area can sometimes be nested across multiple sheets and assembled, or we can discuss alternatives. Structural shapes, bar stock, and pipe are not cut on the plasma table — if you need those materials, a local steel service center or structural steel supplier is the right source.

To get a quote for your flat parts, upload your DXF here. If you're still working on your drawing, see what materials and thicknesses are currently available on our services page.

Data in this guide comes from ASME B36.10M (2018), AISC Steel Construction Manual (14th/15th edition), ASTM A6, A36, A500, A572, and manufacturer gauge tables. If you find a discrepancy, please contact us — we maintain this as a live document.