We are Riddhi Siddhi Impex, a Mumbai-based Stainless Steel 301 Foils manufacturer, supplier, and exporter, established in 2002. We cold roll and precision slit Type 301 foil to ASTM A666 / ASME SA-666 from 0.03 mm to 0.08 mm. Our ISO 9001, 14001, and 45001-certified company holds ready stock from Soft to Full Hard.
Stainless Steel 301 foils are thin, cold-rolled strips of a metastable austenitic grade holding 16 to 18% chromium and 6 to 8% nickel. The lean nickel content gives 301 a high work-hardening rate. As the foil is cold worked, austenite transforms to martensite, so tensile strength climbs sharply with each temper. This makes AISI 301 foil the standard choice for high-strength springs.
We, as a leading stainless steel 301 foils supplier, process every 301 stainless steel foil in-house, to ASTM A666 for the cold-worked tempers. Buyers can specify tempers from Soft through Full Hard, BA, or 2B surfaces, and slit, deburred, or round edges. Mill test certificates accompany each order.
Temper describes how much cold work sits in the foil after the final rolling pass, and it sets the strength you get before any forming begins. We hold Type 301 foil in five conditions, from Soft through Full Hard, and all five are defined tempers under ASTM A666 with published tensile and yield minimums. That is unusual. Most mills only stock other austenitic grades up to half hard, so 301 is the grade we point buyers to when a hard temper needs a certificate value behind it rather than an agreed range.
Buyers who intend to deep draw or roll form the part come to us for annealed 301 first. The foil starts at 515 MPa tensile and 205 MPa yield with 40% elongation, giving the widest forming window of any condition on this page. Work hardening then does the rest, so a part pressed from soft foil finishes stronger than the coil it came from. The trade-off shows on our slitting line: soft foil at 0.03 mm is prone to coil set and needs paper interleaving on narrow widths to arrive flat.
Quarter hard is the temper we quote when a stamping shop has trouble holding form in annealed material but still needs a bend radius. ASTM A666 sets it at 860 MPa tensile and 515 MPa yield with 25% elongation, roughly 65% above annealed on tensile while keeping a quarter of the ductility. Light forming, shallow draws, and simple bends run without cracking at this level. Springback increases noticeably against soft foil, so press tooling usually needs a small overbend allowance.
This condition covers most of the clamp and clip work we ship. A666 minimums are 1035 MPa tensile and 760 MPa yield at 18% elongation, which carries real load in thin section without moving into brittle territory. Hose clamps, retaining clips, and formed brackets sit here because the part holds its set after release. Blanked parts also stay flat, which solves the complaint we hear most often about soft foil coming off the press with a curl.
Three quarter hard is where 301 pulls clearly ahead of 304 and 316. All three grades have the temper defined in A666, but 301 reaches it with less reduction because of its higher work hardening rate, so it is the grade mills actually stock hard.Tensile reaches 1205 MPa and yield 930 MPa, with elongation down to 12%. Contact springs, connector clips, and constant force springs use it where deflection has to recover cycle after cycle. Forming at this level is limited to gentle radii, so if the design needs both this strength and a real draw, split the operation and form soft, then look at post-form work hardening instead.
Full hard is the maximum standard condition we supply, at 1275 MPa tensile and 965 MPa yield with 9% elongation. It goes into flat springs, shim stock, diaphragm springs, and EMI shielding strip where the part is flat or lightly formed. Bending at this temper is a straight line to fracture unless the radius is generous and the bend runs across the rolling direction. One practical note on certificates: at 0.03 to 0.08 mm no Rockwell C reading is meaningful, so our EN 10204 3.1 certificate records temper by tensile test, and the elongation figures on this page read as indicative at foil gauge rather than as A666 minimums, since the standard applies reduced values below 0.38 mm.
We provide ASTM A666 Type 301 foil in tempers from Soft to Full Hard, with a choice of surface finishes and four edge options, precision slit to requirement.
| Parameter | Details |
|---|---|
| Standard | ASME SA-666, ASTM A666 |
| Thickness | 0.03 mm to 0.08 mm |
| Width | 3 mm to 2000 mm |
| Width Tolerance | ±0.1 mm |
| Temper | Soft (Annealed), ¼ Hard, ½ Hard, ¾ Hard, Full Hard |
| Surface Finish | BA (Bright Annealed), 2B, Matte, Skin Pass |
| Edge | Slit edge, Mill edge, Deburred edge, Round edge |
Chromium and nickel define this grade. The 16 to 18% chromium forms a passive oxide for corrosion resistance, while the lean 6 to 8% nickel keeps the austenite metastable and drives the strain-hardening effect. The full ASTM A666 composition appears below.
| Element | Composition (%) |
|---|---|
| Chromium (Cr) | 16.0 to 18.0 |
| Nickel (Ni) | 6.0 to 8.0 |
| Carbon (C) | 0.15 max |
| Manganese (Mn) | 2.00 max |
| Silicon (Si) | 0.75 max |
| Phosphorus (P) | 0.045 max |
| Sulphur (S) | 0.030 max |
| Nitrogen (N) | 0.10 max |
The defining feature of AISI 301 foil is how strength rises with cold work. Annealed material starts at a minimum tensile strength of 515 MPa tensile and reaches 1275 MPa at Full Hard. We supply the full temper ladder to ASTM A666, with a density of about 7.9 g/cm³.
| Temper | Tensile min (MPa / ksi) | Yield min (MPa / ksi) | Elongation min (%) |
|---|---|---|---|
|
Soft (Annealed)
|
515 / 75 | 205 / 30 | 40 |
|
¼ Hard
|
860 / 125 | 515 / 75 | 25 |
|
½ Hard
|
1035 / 150 | 760 / 110 | 18 |
|
¾ Hard
|
1205 / 175 | 930 / 135 | 12 |
|
Full Hard
|
1275 / 185 | 965 / 140 | 9 |
International buyers can cross-reference UNS S30100 foil against their regional standard below. Every Spring Temper 301 foil we slit matches these designations.
| Country / Standard | Designation |
|---|---|
| USA (UNS) | S30100 |
| Europe (EN) | X10CrNi18-8 |
| Germany (W.Nr) | 1.4310 |
| Japan (JIS) | SUS 301 |
| China (GB) | 12Cr17Ni7 |
| Russia (GOST) | 12Kh18N9 |
| France (AFNOR) | Z11CN18-08 |
These 4 industries specify most of the Stainless Steel 301 foils we slit, chosen for the grade's work-hardening rate and spring strength.
Automotive suppliers use 301 stainless steel foil for flexible couplings, exhaust flex components, hose clamps, and diaphragm springs. High tensile strength at Half and Full Hard temper lets thin parts carry load, and forming itself strengthens the part.
Aerospace fabricators specify tempered 301 foil for formed brackets, retaining springs, and shim stock. Full Hard material meets weight-saving targets, and the annealed temper forms complex shapes before work hardening.
Electronics makers use AISI 301 foil for contact springs, connector clips, EMI shielding strips, and battery tabs. The spring temper holds contact force through cycling, and tight thickness control suits stamping and etching.
General engineering shops fit 301 stainless steel foil into constant-force springs, retaining rings, gaskets, and formed clips. The grade work hardens during pressing, so parts gain strength as they are formed.
Export orders are issued from our Mumbai and Taloja warehouses in wooden cases or on pallets.
| Parameter | Details |
|---|---|
| Packaging | Wooden cases, pallet packing |
| Incoterms | FOB, CIF, CFR, EXW Mumbai |
| Dispatch Points | Mumbai and Taloja warehouses |
| Standard Lead Time | 4 to 5 days |
| Urgent Dispatch | 2 to 3 days |
| Payment Terms | Advance, credit, LC |
| Certification | EN 10204 Type 3.1 / 3.2 on request |
The stainless steel 301 foil price range in India is around ₹190-₹320 per kg. For international buyers, it is generally USD 1.00-USD 3.00 per kg. Temper, thickness, width, finish, and quantity all move the figure, so call or WhatsApp for today's rate.
We slit Stainless Steel 301 foil from 0.03 mm to 0.08 mm thick and to any width between 3 mm and 2000 mm, held to ±0.1 mm on width. Temper and finish follow your order.
Stainless Steel 301 foils are available in five tempers: Soft (Annealed), Quarter Hard, Half Hard, Three-Quarter Hard, and Full Hard. Each has defined tensile strength and Rockwell hardness values under ASTM A666.
Stainless Steel 301 foils are covered by ASTM A666 / ASME SA-666 for chemistry and annealed properties, and for the cold-worked tempers.
The main difference is lower nickel at 6 to 8% against 8 to 10.5% in 304, which lets it work harden further. This gives 301 higher tensile strength after cold rolling, so it suits springs. Type 304 resists corrosion better.
Standard dispatch runs 4 to 5 days from ready stock, and urgent orders can leave in 2 to 3 days. We hold 301 foil across common tempers.
You can source Stainless Steel 301 foils in India from us at Riddhi Siddhi Impex. Our Mumbai warehouse holds 301 foil on the shelf for immediate dispatch. As a manufacturer, stockist, and exporter, we serve buyers across India and overseas, and we send a quote within 24 hours.
