Laser Cut Stainless Steel (304 & 316)

304 or 316?

304 is the everyday stainless. Its chromium forms a thin, self-healing surface film that keeps it from rusting in air, fresh water and contact with most cleaners, which is why it's used for food-service and kitchen equipment parts, architectural trim, signage, and indoor or outdoor work away from pools and salt.

316 adds molybdenum, which helps that film stand up to chlorides: salt, pool chemicals, salt-water pools and spas, and harsh cleaners. Choose it for pool and spa hardware, anything in salt air or salt water, and parts that get splashed with chemicals. Boats on Lake Mead and Lake Mohave sit in fresh water, where 304 usually holds up; parts that will also see the ocean call for 316.

The two grades aren't always stocked in the same thicknesses, so compare the two lists on this page before settling on one. If a drawing calls for 304L or 316L, the low-carbon versions often specified for heavily welded parts, ask the shop before ordering.

Stainless parts and their thickness

Stainless work splits into two kinds. Show parts — backsplashes, equipment panels, kick plates, trim, plaques and letters — are usually thin sheet, chosen for flatness and looks, with stiffness coming from folds, a frame or the wall behind. Working parts — brackets for wet locations, pump and pool-equipment mounts, boat hardware and machine guards — are sized for their load like steel parts, since stainless is about as stiff and as heavy as mild steel.

Stainless is often described by gauge but usually sold by the decimal, so put the decimal on drawings and orders; the sheet metal gauge chart shows each stainless thickness in stock that way. Railing infill, cladding and decorative screens are covered in the architectural metal guide, and plaques and lettering in the signage guide.

Designing for the laser

The laser cuts all the way through the sheet, so draw outlines, cutouts, holes and slots — not pockets or partial-depth holes. Keep holes at least about half the material thickness across so they cut cleanly; the quote flags anything smaller before you order.

Lines you set to engrave are etched on the surface instead of cut through — handy for part numbers, logos and bend or layout marks.

Bending, fastening and marking stainless

Stainless is harder to form than mild steel: it needs more force and springs back further after a bend, so give parts you'll bend generous inside radii, with bend reliefs where a bend line meets an edge. It also work-hardens — a dull drill or tap rubs instead of cutting and hardens the hole as it goes — so for holes you'll thread later, draw the tap-drill size and use sharp tools with steady pressure, or design in rivet nuts or weld studs.

Fasten stainless with stainless hardware. Plain or zinc-plated screws rust and stain the panel around them, and a wet joint between stainless and aluminum, zinc or plain steel makes those metals corrode faster.

On brushed stainless, the grain is part of the look. Parts are nested to save metal, which can turn some of them on the sheet, so if the grain must run the same way on every part — a row of panels or a set of letters — say so in a note for the shop. Etched part numbers and instructions won't peel off the way a label can, which suits equipment that gets washed down.

Keeping stainless clean around pools, misters and hard water

Stainless doesn't need paint, but it does need to stay clean. Iron from steel tools, wire brushes, grinding dust or steel wool can lodge in the surface and rust there, leaving orange specks that look as if the stainless itself is failing. Keep stainless away from steel work, clean it with stainless-safe products and a soft cloth or nylon pad, and wipe along the grain on brushed finishes.

Las Vegas water is hard, so sprinklers and patio misters leave white mineral spots that dull the finish; wipe them off before they build up. Around pools and spas, chlorine and salt concentrate as water evaporates in the heat, which is where 304 can pit or stain tea-brown and 316 keeps its look longer. Rinsing pool-side hardware with fresh water now and then helps either grade.

Brushing, polishing and electropolishing are finishing steps for after cutting, and welding leaves a heat tint beside the bead that should be cleaned off parts headed for wet or outdoor service — see the passivation question below.

What a stainless order includes

Stainless parts ship flat and as cut, with the faces as the mill supplied them. Bending, welding, deburring, brushing or polishing, and passivation aren't part of a laser order, so your fabricator or finisher takes it from there. For a finished assembly rather than parts — a railing panel, a hood surround, a counter — send a custom fabrication inquiry. Railings, tube frames and turned or hardened parts are covered in the questions below.

How it's priced

Each part is priced on its cut length, each hole by its size, its pierces and any etched lines, plus setup and programming once per design, handling for each piece and loading for each sheet the job uses. Metal is billed by the area your parts use — each part's outer size plus a little cutting space — never more than the sheets they're cut from, and identical parts get automatic quantity discounts on the cutting.