Automotive and Off-Road Accessory Parts, Laser-Cut

The parts this page covers

An off-road or automotive accessory part here is a flat or bent plate part bolted or welded onto a vehicle: a skid plate blank, a bumper or roof-rack bracket, a light-bar or antenna mount, a frame tab, a gusset, a dash or switch panel with cutouts, a spacer plate. It is cut to the print, bent where the print shows a bend, tapped or fitted with hardware if called out, powder coated or left bare as written, inspected and shipped. The laser-cut parts hub explains how one order covers all of that; this page covers what the print should name for these parts.

What this page does not cover is the engineering of the part. A skid plate, bracket or mount is made to the buyer’s print, and the quote covers cutting, forming and finishing it as drawn; no claim is made here about how a part will perform, fit or hold up on a vehicle. A sketch, a new sample bracket or a template cut from cardboard is enough to get a quote; the CAD work is then quoted as its own line, and the quote lists anything the drawing is missing. A fully dimensioned 2D PDF is quoted without a CAD line. The general bracket family is on laser-cut brackets and mounts, and the automotive and motorsport page covers the machined side of the same customers.

Mild steel: 1008 cold-rolled sheet and A36 plate

Mild steel welds readily: Wikipedia’s A36 page says the grade is readily welded by all welding processes (source 2). On this page, thinner parts mean 1008 cold-rolled sheet and heavier ones A36 hot-rolled plate. Cold rolling gives a better surface finish and tighter tolerances than hot rolling, whose surface is covered in mill scale (source 3); pickling removes scale and rust from hot-rolled steel, and a thin film of oil is applied afterward as a barrier to moisture (source 4). Name the material and thickness on the print.

A36 is the grade to write on a plate print. ASTM A36/A36M is the Standard Specification for Carbon Structural Steel and covers shapes, plates and bars for riveted, bolted or welded construction of bridges and buildings and for general structural purposes (source 1); Wikipedia gives a minimum yield strength of 36 ksi (250 MPa) in thicknesses under 8 in (source 2). The downside is plain: iron rusts when it is in contact with water and oxygen, and a coating such as paint isolates the iron from the environment (source 5). Outdoors, that is why a coating such as powder coat goes on the print. The laser-cut steel page covers the grades in more depth.

Aluminum: 5052-H32 for bends, 6061-T6 for flat plates

5052-H32 is the aluminum for a bracket with flanges; 6061-T6 is the aluminum for a flat plate that stays flat. Hydro’s bending guide calls 5052 a popular choice for sheet metal work where bendability and corrosion performance both matter, says the bending ability of 6061 drops significantly in the T4 and especially the T6 temper, and says harder tempers like T6 need wider bend radii to avoid cracking (source 8), so a 6061-T6 bend wants a wider inside radius. The inside radius is quoted as drawn, with a note if it won’t form.

Wikipedia lists 6061-T6 at a yield strength of at least 240 MPa (source 7) and 5052-H32 at 193 MPa (source 6), and credits 5052 with exceptional resistance to seawater and salt spray (source 6). The print carries alloy, temper and thickness ("6061-T6, 0.250 in") so there is no guessing at the quote. A 6061 plate with pockets, counterbores or a flat that has to be machined is the point where the part becomes a milled part; billet aluminum parts covers that route and it is quoted on the same request. The laser-cut aluminum page has the full grade comparison. Other alloys and plastics quoted on request. Name the grade on the print.

Bends, weld tabs, tapped holes and hardware

A bent bracket carries bend angle, inside radius and bend direction on the print. A bracket that must clear a frame rail by a fixed gap is drawn with that gap dimensioned. Laser-cut bent brackets covers the callouts.

A chamfer or weld bevel on a tab or gusset edge is called out on the print with its angle and quoted from the print. The welding of the tab to the vehicle is the buyer’s work unless the print shows a welded assembly, which is welded to the print and covered on laser-cut welding. Tapped holes are written by thread size and depth. A PEM nut or stud is written by part number, and hardware is installed per the print; hardware insertion covers the callouts. The print says whether threads that will not be coated are masked, or chased after coating.

Powder coat and bare steel: what to put on the print

Powder coat is a film with thickness: Wikipedia notes that film build-ups of greater than 50 μm may be required for an acceptably smooth film (source 9), which matters on a part with a slip fit or a tapped hole. On a print that means: name the color and gloss, mark masked areas, and say whether tapped threads are masked or chased after coating. A finish called out on the print is quoted with the part.

Bare steel is a legitimate callout when the buyer will weld the bracket in and paint the assembly, and the print simply says "no finish" or "HRPO (hot-rolled, pickled and oiled), as cut." For aluminum, Type II anodize, undyed or dyed black, is called out on the print (source 10); powder coat is the other choice. Finishes are quoted with the parts cut here; a finish-only job on a part you already have is not quoted. The laser-cut finishing page and the powder coating service page carry the callout details; the site-wide list is on CNC surface finishes.

Tolerances, inspection and what to send

On accessory parts the tolerances that matter are hole position to the mating bolt pattern and the bent dimension that sets clearance. A hole that must line up with a factory bolt pattern should carry a position tolerance rather than a general note. Position, perpendicularity and runout callouts are quoted from the print. A bore that must be tighter than the cut allows is quoted as a machined feature on the same order, covered on laser-cut, tapped and machined as one order. The laser-cut tolerances page explains the classes.

Every part inspected against your print before it ships. If a part doesn’t match the print, it’s remade or credited. To get a quote, send a DXF or STEP plus a PDF print if you have one; any file type is accepted, and a dimensioned sketch, a cardboard template with a ruler in the photo, or a new sample bracket is enough to start. Machined brackets in thicker stock are on custom CNC brackets. Start at the quote form: no minimum, lead time quoted per job with rush available.

Sources

All accessed 4 October 2026. Where a figure here differs from your print, the print governs.

1. ASTM International, "A36/A36M-19, Standard Specification for Carbon Structural Steel": store.astm.org/a0036_a0036m-19.html (shapes, plates and bars; riveted, bolted or welded construction of bridges and buildings and general structural purposes; listed as the active edition).

2. Wikipedia, "A36 steel": en.wikipedia.org/wiki/A36_steel (36 ksi, 250 MPa minimum yield under 8 in; readily welded by all welding processes).

3. Wikipedia, "Rolling (metalworking)": en.wikipedia.org/wiki/Rolling_(metalworking) (cold rolling improves surface finish and holds tighter tolerances; hot-rolled surface covered in mill scale).

4. Wikipedia, "Pickling (metal)": en.wikipedia.org/wiki/Pickling_(metal) (removes rust and scale from ferrous metals; a thin film of oil applied afterward as a moisture barrier).

5. Wikipedia, "Rust": en.wikipedia.org/wiki/Rust (iron rusts in contact with water and oxygen; coatings such as paint isolate the iron from the environment).

6. Wikipedia, "5052 aluminium alloy": en.wikipedia.org/wiki/5052_aluminium_alloy (H32 yield 193 MPa; resistance to seawater and salt spray).

7. Wikipedia, "6061 aluminium alloy": en.wikipedia.org/wiki/6061_aluminium_alloy (T6 yield strength of at least 240 MPa).

8. Freddy Leijon, "Here are the best aluminum alloys for bending: a complete guide", Hydro, 13 January 2021: shapesbyhydro.com/en/knowledge/here-are-the-best-aluminium-alloys-for-bending/ (5052 a popular choice for sheet metal work where bendability and corrosion performance matter; 6061 bending ability drops in T4 and especially T6; harder tempers like T6 need wider bend radii).

9. Wikipedia, "Powder coating": en.wikipedia.org/wiki/Powder_coating (film build-ups over 50 μm may be required for a smooth film).

10. Wikipedia, "Anodizing": en.wikipedia.org/wiki/Anodizing (Type II sulfuric acid anodizing, MIL-A-8625 Types II and IIB, AMS 2471 undyed and AMS 2472 dyed; a porous surface that accepts dyes; each surface grows by half the oxide thickness).