We are Riddhi Siddhi Impex, a Mumbai-based Hastelloy C276 shims manufacturer and supplier, established in 2002. Our in-house slitting of Alloy C-276 (UNS N10276) shims to ASTM B575 from 0.03 to 5 mm maintains a ±0.1 mm width tolerance. Our ISO 9001, 14001, and 45001-certified company and our Hastelloy shim supply capacity is around 400-500 tonnes monthly with EN 10204 Type 3.1 / 3.2 mill test certificates available on request.
Hastelloy C276 shims are thin, flat spacers slit from a nickel-molybdenum-chromium alloy that carries a tungsten addition. Molybdenum at 15 to 17% and chromium at 14.5 to 16.5% give the grade its resistance to pitting, crevice attack, and reducing acids. Density sits near 8.89 g/cm³. Fabricators fit these shims wherever a gap must be filled accurately in corrosive service between flanges, under bearing housings, and inside instrument assemblies.
We process every C276 shim in-house on our own slitting lines rather than reselling standard widths. Material is slit to widths from 3 mm to 2000 mm before dispatch, held soft annealed or cold worked to the temper you specify. Buyers can choose BA, 2B, Matte, or Skin Pass surfaces. A documented quality system governs each stage, from source coil inspection through dispatch.
Temper describes how much cold work a shim retains after its final anneal, which sets both its strength and its springback. We supply six conditions, from soft annealed to full hard. ASTM B575 defines only the solution annealed state for this grade; the five harder conditions are mill tempers, rolled on our own lines to tensile ranges agreed at order stage and recorded on the EN 10204 mill test certificate. On shim work the decision carries real weight, since temper decides whether a 0.05 mm spacer keeps its thickness under clamping load or slowly deforms in service.
Solution annealed is the one condition ASTM B575 actually defines: 690 MPa minimum tensile strength, 283 MPa yield, 40% elongation, and hardness no higher than 100 HRB. It is also the only state whose corrosion behaviour the specification stands behind, which is why acid-service and pressure-boundary shims should stay annealed. The soft material conforms closely to flange faces and machined seats, taking up surface irregularities that a stiffer shim would bridge. For this temper our mill test certificate reports the B575 test results directly, with no agreed ranges needed.
Quarter hard is the temper we quote when an order asks for shims that resist handling damage without giving up formability. Rolled to an indicative 830 to 1000 MPa tensile band, it carries hardness between 96 HRB and 20 HRC. Thin gauges gain enough stiffness to go into tight assemblies by hand without creasing. Enough ductility remains for fitters to dress a shim around a housing radius on site.
The complaint that moves buyers up to half hard is annealed shim packs compressing under sustained bolt load and letting a set clearance drift. At 1000 to 1170 MPa indicative tensile and 20 to 28 HRC, the condition resists that thinning and keeps flange and bearing gaps where the fitter left them. Springback rises noticeably, so forming is limited to open bends. Valve and pump alignment packs are the usual destination for this temper.
On the slitting line, three-quarter hard stock springs back harder than the softer conditions, so we adjust tension settings to hold camber at narrow widths. The material runs 1170 to 1310 MPa at 28 to 34 HRC, stiff enough to slide into a tight gap without buckling. Forming stops at gentle curves; sharp bends will crack the edge. At the thinnest gauges we confirm temper by tensile test or microhardness rather than Rockwell, since thin stock cannot support the indenter, and the certificate states which method applied.
Instrument builders specify hard temper for preload spacers and anti-vibration packs that must push back against load cycle after cycle. Indicative tensile sits at 1310 to 1450 MPa with 34 to 40 HRC hardness. Parts at this level are blanked or slit straight to finished size, because meaningful forming is no longer practical. Deburred or round edges are worth specifying here; a hard slit edge is sharp enough to score adjacent seal faces during fitting.
Full hard is the wrong buy for any shim whose first job is corrosion sealing, because heavy cold work alters the structure and the corrosion guarantees behind ASTM B575 apply to solution annealed material only. Where a design needs pure spring strength with no acid or chloride exposure, full hard stainless steel 301 does the same mechanical work at a far lower price, and we say so at quotation. Buyers who need C276 chemistry and maximum stiffness together get stock rolled towards 1450 to 1655 MPa at 40 to 45 HRC. Flatness after slitting is the property we watch most closely at this temper, since fully worked material holds any coil set it is allowed to keep.
We provide ASTM B575 Hastelloy C-276 shim stock from 0.03 mm to 5 mm thick, with four surface finishes and three edge options.
| Parameter | Details |
|---|---|
| Standard | ASTM B575 / ASME SB-575 |
| Thickness | 0.03 mm to 5 mm |
| Width | 3 mm to 2000 mm |
| Width Tolerance | ±0.1 mm |
| Surface Finish | BA (Bright Annealed), 2B, Matte, Skin Pass |
| Edge | Slit edge, Deburred edge, Round edge |
Molybdenum at 15 to 17%, working with tungsten at 3 to 4.5%, sets Alloy C276 shims apart. The combination resists pitting and crevice corrosion in chloride media, while the 0.01% carbon ceiling limits carbide precipitation. The full ASTM B575 composition follows.
| Element | Composition (%) |
|---|---|
| Nickel (Ni) | Balance |
| Molybdenum (Mo) | 15.0 to 17.0 |
| Chromium (Cr) | 14.5 to 16.5 |
| Iron (Fe) | 4.0 to 7.0 |
| Tungsten (W) | 3.0 to 4.5 |
| Cobalt (Co) | 2.5 max |
| Manganese (Mn) | 1.0 max |
| Vanadium (V) | 0.35 max |
| Carbon (C) | 0.01 max |
| Silicon (Si) | 0.08 max |
| Phosphorus (P) | 0.04 max |
| Sulphur (S) | 0.03 max |
In the annealed condition to ASTM B575, Alloy C-276 shims carry a minimum tensile strength of 690 MPa, a yield of 283 MPa, and 40% elongation. Because the alloy hardens only by cold work, we supply the six-condition temper ladder with hardness stated by tensile range and Rockwell. The annealed row gives the ASTM B575 minimums; the cold-worked rows are indicative.
| Temper Condition | Tensile Strength (MPa) | Rockwell Hardness |
|---|---|---|
|
Soft (Annealed)
|
690 min | 100 HRB max |
|
Quarter Hard
|
830 to 1000 | 96 HRB to 20 HRC |
|
Half Hard
|
1000 to 1170 | 20 to 28 HRC |
|
Three-Quarter Hard
|
1170 to 1310 | 28 to 34 HRC |
|
Hard
|
1310 to 1450 | 34 to 40 HRC |
|
Full Hard
|
1450 to 1655 | 40 to 45 HRC |
International buyers can cross-reference UNS N10276 shims against their regional standard below. Our C276 shims match every designation listed here.
| Country / Standard | Designation |
|---|---|
| USA (UNS) | N10276 |
| Europe (EN) | NiMo16Cr15W |
| Germany (W.Nr) | 2.4819 |
| Japan (JIS) | NW 0276 |
| China (GB) | NS3304 |
These 4 industries utilise most of the Nickel Alloy C276 shims we slit. In each case, buyers select the grade for its resistance to acids and chlorides rather than for strength alone.
Chemical plants fit Alloy C-276 shims around reactor flanges, heat exchangers, and gasket faces. Molybdenum and tungsten resist hydrochloric and sulphuric acid where stainless spacers corrode within months. The grade holds its thickness without pitting, keeping flange gaps accurate through long service runs.
Sour-service assemblies use C276 shims to set clearances in valves, seals, and instrumentation. The grade withstands high-chloride and hydrogen sulphide environments without stress corrosion cracking. Precision-slit to ±0.1 mm, each shim arrives ready for installation, so field crews avoid on-site trimming in hazardous locations.
Hygienic equipment relies on Hastelloy C276 shims where cleaning acids and repeated sterilisation would attack lesser metals. The alloy holds a clean, non-contaminating surface through hot alkaline washdown cycles. Fabricators fit the shims to align shafts and set seal faces in mixers and filling machinery.
Flue gas desulphurisation units and scrubber internals take Nickel Alloy C276 shims to handle acidic condensate and chloride-laden gas. Wet chlorine and sulphurous compounds degrade carbon steel quickly, while C276 serves for years. The shims align duct sections, dampers, and instrument mounts inside these gas streams.
Export orders leave from our Mumbai and Taloja, packed in wooden cases or on pallets, ready for sea.
| 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 |
Hastelloy C276 shims price range in India is around ₹3,200 to ₹6,500 per kg. For export, it is generally $34 to $68 per kg. The price moves with global nickel and molybdenum exchange rates. Thickness, width, temper condition, quantity, and finish all affect the figure. Volume discounts apply to bulk orders, so call or WhatsApp us for today's rate.
We slit Hastelloy C276 shim stock from 0.03 mm to 5 mm thick and to any width between 3 mm and 2000 mm. Anything below 0.03 mm falls under our Hastelloy C276 foils range.
Hastelloy C276 shims are available across the full ladder: soft annealed, quarter hard, half hard, three-quarter hard, hard, and full hard. Each condition is specified by its tensile range and Rockwell hardness.
Some of the surface finishes we offer on Alloy C276 shims are BA, 2B, Matte, and Skin Pass. Round or deburred edges suit gasket and instrument work where a sharp slit edge would damage adjacent parts.
You can source Hastelloy C276 shims in India from us at Riddhi Siddhi Impex. Our Mumbai warehouse holds C276 shim inventory ready for dispatch. As a manufacturer, supplier, and exporter since 2002, we serve buyers across India and export overseas. Phone or WhatsApp us; we provide quotations within 24 hours.
