Materials
Coil materials we form
Cold-roll 1010 and 1018, medium-to-high spring steels, the 300-series stainlesses including 330, brass, and copper — all from coil, in the 4–14 mm band, with 3/8, 7/16, and 1/2 in as stock diameters.
What we process from coil
Wire forming starts with a coil, not a bar. The cert on that coil is the process: alloy, tensile or temper, coating, and diameter. “Spring steel” and “stainless” are not grades. They are how first articles fail.
Production here is 4–14 mm (0.157–0.551 in), stock sizes 3/8, 7/16, and 1/2 in. Other coil in the band still runs. Music-wire clips and 0.020 in 302 are a different cell — explained on the map, not quoted as 1/2 in work.
What the print has to name
- AISI / UNS / ASTM grade — 1018, 304, 330, C260, not a family name
- Tensile, temper, or condition (annealed, hard-drawn, oil-tempered)
- Coating: bare, galvanized class, pre-paint — and whether it is pre- or post-form
- Diameter as a number, not “or equivalent 7/16”
Swapping 304 for 302, or 1010 for 1060, without a new article changes springback, weld, and sometimes the crack at the inside radius. Detail: design for wire forming.
Cold-roll carbon: 1010, 1018, and neighbors
1010 and 1018 are the stock carbon coils. Cold-rolled / cold-drawn forming wire, not hot-roll bar. They weld with resistance and MIG, take zinc and powder after form, and hold a 1× diameter inside radius on mild coil. Frames, grids and cable trays, guards, and most 2D/3D industrial forms start here.
| Grade | In the cell |
|---|---|
| 1010 | Stock cold-roll forming wire. Soft, welds clean, 1× diameter inside radius on mild coil. |
| 1018 | Stock cold-roll. Slightly stronger than 1010. Default carbon for frames, trays, and grids. |
| 1006 / 1008 | Softer drawing grades. Used when the form is severe or the coating is picky. |
| 1008 / 1010 galvanized | Pre-coated coil. Expect mark in the straightener and burn-back at every weld. |
Medium and high spring steels
Once carbon and draw go up, the part is a spring whether the print says so or not. Springback compensation lives in the program. Min inside radius moves toward 1.5–2× diameter. Hydrogen bake after acid zinc is not optional on high-tensile.
We run medium-to-high spring steels from coil in this band when the head, the radius, and the tensile fit. Hard-drawn and oil-tempered industrial grades at 3/8–1/2 in are real jobs. ASTM A228 music wire is usually far below 4 mm — a different trade, still listed so it is not confused with 1018.
| Grade | In the cell |
|---|---|
| 1030–1045 | Medium carbon. More springback than 1018. Stress-relieve after a tight 3D path if the print cares. |
| 1050–1060 HD | Hard-drawn medium-high carbon. Industrial springs and clips at the light end of the band. |
| 1070–1095 | High-carbon spring. Large radius, real tensile. Confirm the head at 3/8–1/2 in. |
| A229 oil-tempered | MB spring wire, oil tempered. Common industrial spring coil; not a 1018 substitute. |
| A228 music wire | Very high tensile. Usual diameters are well under 4 mm. We explain it; we do not pretend it is 1/2 in frame wire. |
| 6150 / 5160 / CrSi | Alloy spring. Chrome-silicon and 6150 show up on heavy springs and torsion parts. Radius and bake after plate matter. |
300-series stainless, from coil
Austenitic 300-series is the stainless we form. Deep page: 300-series stainless. More springback than 1018, more galling in tools, passivate after form and weld — not paint. Do not write “SS” on a grid that has to live in a furnace. That is how 304 gets quoted as 330.
| Grade | Coil notes |
|---|---|
| 301 | Work-hardens fast. Springier than 304. Watch min radius and tool galling. |
| 302 | Classic stainless forming wire. A bit more carbon than 304, more snap. Common clip and form grade. |
| 304 / 304L | General 300-series coil. Food, architectural, outdoor grids. 304L when weld carbide precipitation is a spec. |
| 305 | Lower work-hardening. Used when a severe cold form would crack 304. |
| 316 / 316L | Molybdenum, better chloride resistance. More expensive, more springback than 304. Marine and chemical. |
| 317 / 317L | Higher Mo than 316. Spec-driven, not a default coil. |
| 309 / 310 | Higher Cr/Ni, heat and oxidation. Furnace-adjacent; still not 330. |
| 321 / 347 | Ti- or Nb-stabilized. Welded high-temp service when 304L is not the spec. |
| 330 (N08330) | Stock high-temp coil for heat-treat wire baskets and furnace fixtures. Ni-Cr, not “stainless 304 with a bigger number.” |
| 201 / 202 | Mn austenitics. Sometimes substituted for 304. Call the real grade; do not accept “equiv.” |
303 is a free-machining grade. It is not a forming coil we stock or recommend. If the print says 303 wire, ask whether they meant 304 or 302.
330 stainless in coil
330 (UNS N08330) is a nickel-chromium high-temperature alloy sold as wire and rod. It is the usual coil for heat-treat wire baskets, furnace fixtures, and grids that see air at temperature that would scale 304 in a week. It is not “high 300-series.” Nickel content, price, and forming load are in another class.
- Stock topic for heat-treat wire baskets and rod frames in this shop’s diameter band
- Inside radius on the generous side — treat it like high-Ni, not like 304
- TIG is the honest join on a lot of 330 fixtures; confirm resistance weld before you assume a grid nugget
- Service temperature and load belong on the quote, not just “330 wire basket”
Brass and copper
Soft coil, tight radii, easy to mark, easy to overbend. Electrical forms, grounding, decorative grids, and any part that cannot be steel. Tools and straighteners that are right for 1018 will skate or bruise C110. Keep a clean, dedicated setup.
| Grade | Coil notes |
|---|---|
| C110 ETP copper | Soft, marks, excellent conductivity. Tight radii possible. Keep tools clean. |
| C102 OFHC | Oxygen-free. Electrical and vacuum-adjacent when C110 is not allowed. |
| C260 / C270 brass | Cartridge / yellow brass. Common formed brass wire. Annealed coil forms; hard coil springs back. |
| C230 red brass | Higher copper, redder color, a bit softer than C260. |
| C510 phosphor bronze | Electrical spring. Different modulus than steel; do not copy a 1018 radius. |
Finish is usually none, or a specified lacquer / plate. Welding copper and brass is not the same as welding 1018 — say if the joint is soldered, brazed, or fusion-welded.
Coatings on steel coil
Pre-galvanized and pre-painted carbon is cheaper at volume and ugly at a tight inside radius. Welds burn the coat locally. Form-then-zinc or form-then-powder is the cleaner path on 3/8–1/2 in frames and trays. Stainless is passivate. Full sequence: plating and coating.
How grade meets 3/8, 7/16, and 1/2 in
| Size | Typical coil | Watch |
|---|---|---|
| 3/8 in | 1010 / 1018, 304, 316, C260, medium spring | Pre-galv mesh; 301 work-hardening on a tight path |
| 7/16 in | 1018, 304, 330 rims, higher-carbon spring | Do not swap 3/8 and 7/16 to “use stock” |
| 1/2 in | 1018 frames, 330 fixtures, heavy 304, high-carbon | Head, IR, and weld force — this is fabrication that started as wire |
400-series (410, 430) and aluminum show up on prints. We will say whether that coil belongs in this cell. Inconel and other nickel alloys beyond 330 are a cert-and-conversation job, not a 1018 setup with the pressure turned up.
Related
- Wire fabrication, 4–14 mm — carbon, stainless, ferrous, and non-ferrous
- 300-series stainless — 301 through 330
- 3/8, 7/16, and 1/2 in
- Quotes, tooling, and coil — mill minimums when we do not carry the steel
- Design for wire forming
- Heat treating — 330 wire baskets vs stress-relief
- Plating and coating
- 3D CNC wire forming