We are Riddhi Siddhi Impex, a Mumbai-based Incoloy 840 shims manufacturer and supplier, established in 2002. We slit shims from this titanium and aluminium-bearing 20Cr-20Ni heat-resisting austenitic alloy made to ASTM B424 and ASTM A240 in thicknesses of 0.03 mm to 5 mm. Our ISO 9001, 14001, and 45001-certified firm holds ready stock, a monthly supply capacity of 400-500 tonnes, and issues EN 10204 Type 3.1 / 3.2 mill test certificates upon request.
Incoloy 840 shims are thin, flat spacers slit from a nickel-iron-chromium superalloy built on 20% chromium and 20% nickel, with titanium and aluminium additions and iron as the balance. Those additions bind a tight oxide scale, so the shim resists scaling in air to about 1038 °C. Density is near 7.92 g/cm³. The grade is best known as a sheathing material for electric heating elements, which makes its shims a natural fit for hot assemblies. It is widely used in electric heating equipment and furnace components.
We slit every Alloy 840 shim in-house rather than reselling standard widths. Material leaves in annealed soft condition, in widths from 3 mm to 2000 mm. Buyers choose BA, 2B, or Matte surfaces, and a mill test certificate accompanies each order.
We provide Alloy 840 shim stock in annealed condition, 0.03 mm to 5 mm thick, precision-slit to widths from 3 mm to 2000 mm with a choice of surface finishes and edge options.
| Parameter | Details |
|---|---|
| Standard | ASTM A240 / ASME SA240, ASTM B424 / ASME SB424 |
| Thickness | 0.03 mm to 5 mm |
| Width | 3 mm to 2000 mm |
| Width Tolerance | ±0.1 mm |
| Condition | Annealed (Soft) |
| Surface Finish | BA (Bright Annealed), 2B, Matte, Matte PVC |
| Edge | Slit edge, Mill edge, Deburred edge, Round edge |
| Supply Form | Cold Rolled |
Chromium and nickel share top billing in this grade. UNS S33400 shims hold 18.0 to 22.0% of each, while titanium and aluminium anchor the protective scale. The table follows the alloy producer specification.
| Element | Composition (%) |
|---|---|
| Chromium (Cr) | 18.0 to 22.0 |
| Nickel (Ni) | 18.0 to 22.0 |
| Iron (Fe) | Balance |
| Manganese (Mn) | 1.00 max |
| Silicon (Si) | 1.00 max |
| Titanium (Ti) | 0.60 max |
| Aluminium (Al) | 0.60 max |
| Carbon (C) | 0.08 max |
| Phosphorus (P) | 0.03 max |
| Sulphur (S) | 0.015 max |
Annealed Incoloy 840 shims deliver 572 MPa tensile strength with 40% elongation, so they punch and form cleanly at shim gauges. We supply soft annealed material only; this grade takes no temper ladder. Figures are nominal room-temperature values, indicative of the thinnest gauges.
| Property | Value |
|---|---|
|
Tensile Strength
|
572 MPa (83 ksi) |
|
Yield Strength (0.2% offset)
|
241 MPa (35 ksi) |
|
Elongation in 50 mm
|
40% |
|
Hardness
|
70 HRB |
|
Density
|
7.92 g/cm³ |
International buyers can cross-check the 840 shim stock we slit against the designations below. Unconfirmed entries stay marked until verified, and only verified numbers appear on our paperwork.
| Country / Standard | Designation |
|---|---|
| USA (UNS) | S33400 |
| Germany (W.Nr) | 1.4847 |
These 4 industries widely specify the Incoloy 840 shims we produce. Buyers pick the grade for scaling resistance and dimensional stability at temperatures where standard stainless spacers deteriorate.
Heating-element manufacturers use Alloy 840 shims to space terminal blocks and set clearances inside tubular heater assemblies. Because the shim matches the sheathing alloy, expansion stays uniform from cold start to red heat. The tight oxide grade forms keep packed stacks from scaling shut over repeated cycles.
Furnace builders level burner mounts, align muffle sections, and pack expansion gaps with Incoloy 840 shim stock. The grade resists oxidation, sulphidation, and carburisation under continuous heat. A shim slit to ±0.1 mm drops into place without site trimming, which matters inside an assembled casing.
Exhaust-hardware fabricators choose heat-resistant austenitic stainless steel 840 shims for spacing shields and connectors that are placed in hot, oxidising gas. Chromium and nickel hold the surface stable, where plain stainless spacers scale away. The soft annealed condition lets the shim conform to curved shield profiles during assembly.
Process-plant crews place baffles, seal faces, and heater internals with UNS S33400 shims. The alloy keeps its oxidation resistance to around 1038 °C, so gap settings hold through thermal cycling. Custom-slit widths let each packing point take a single shim rather than a trimmed stack.
Export orders leave from Mumbai and Taloja in wooden cases or on pallets, sea-ready.
| 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 |
Incoloy 840 shims price ranges between ₹160 and ₹190, and around 20-30 USD per kg. We quote each order against current alloy rates, factoring in thickness, width, finish, and quantity. Call or WhatsApp for today's rate.
We slit Incoloy 840 shims from 0.03 mm to 5 mm thick and to any width between 3 mm and 2000 mm. Material thinner than 0.03 mm is supplied through our Incoloy 840 foil range.
Incoloy 840 shims carry the UNS designation S33400 and the German Werkstoff Number 1.4847.
The main difference between Incoloy 840 and Incoloy 800 shims is the base chemistry. Alloy 840 is a titanium and aluminium-bearing 20Cr-20Ni heat-resisting stainless chosen for scaling resistance, while Incoloy 800 carries more nickel for creep duty.
Some of the surface finishes we offer on Alloy 840 shims are BA, 2B, and Matte. Deburred or round edges suit gasket and instrument work where a raw slit edge is unwelcome.
You can source Incoloy 840 shims in India from us at Riddhi Siddhi Impex. Our Mumbai warehouse holds 840 shim stock ready for dispatch. As a manufacturer, supplier, and exporter since 2002, we serve buyers across India and ship overseas. Call or WhatsApp us; we provide quotations within 24 hours.
