SS 321 Machine ScrewASTM A193 · ASME B18.6.3 · Manufacturer, stockist & exporter, India
AISI 321 · UNS S32100
An SS 321 machine screw is a small-diameter screw for equipment assembly, made from SS 321 to ASTM A193 B8T. Machine screws assemble instruments, panels and equipment. Pan, countersunk and cheese heads.
- ASTM A193
- ASME B18.6.3
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an SS 321 Machine Screw?
- What it is
- A small-diameter screw for equipment assembly
- Material
- ASTM A193 B8T
- Dimensions
- ASME B18.6.3 · DIN 84 / 963
- Grade
- SS 321 · UNS S32100
- Best at
- High-temperature service between 425 and 815 °C
SS 321 Machine Screw Specification
| Product | SS 321 Machine Screw |
|---|---|
| Material standard | ASTM A193 B8T |
| Dimensional standard | ASME B18.6.3 · DIN 84 / 963 |
| Sizes | M10 – M64 · ½" – 4" (others on request) |
| Threads | UNC · UN-8 · metric coarse |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose a Machine Screw
Machine screws assemble instruments, panels and equipment. Pan, countersunk and cheese heads.
- Pan, flat and cheese heads
- Slotted or Phillips
- M2 – M10 typical
SS 321 Machine Screw Chemical Composition
| Element | Weight % |
|---|---|
| Chromium | 17.0 – 19.0 |
| Nickel | 9.0 – 12.0 |
| Titanium | 5 × (C + N) min, 0.70 max |
| Carbon | 0.08 max |
| Manganese | 2.00 max |
| Silicon | 0.75 max |
| Nitrogen | 0.10 max |
| Phosphorus | 0.045 max |
SS 321 Machine Screw Mechanical Properties
| Annealed plate & sheet | Value |
|---|---|
| Tensile strength | 515 MPa · 75 ksi |
| Yield strength 0.2% | 205 MPa · 30 ksi |
| Elongation | 40% |
| Hardness | 217 HB max |
Full chemistry, properties and equivalents are on the SS 321 grade page.
Other SS 321 fasteners
SS 321 Machine Screws for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 321 Machine Screw — questions buyers ask
What sizes are machine screws?
Usually small diameters, M2 to M10 or #2 to 3/8".
Which standard covers SS 321 machine screws?
The material is ASTM A193 B8T; dimensions follow ASME B18.6.3 · DIN 84 / 963. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a SS 321 machine screw?
The alloy price, the size and dimensions, quantity, and the testing and documents required. Send your list and we quote the same working day.
What documents do you supply?
EN 10204 3.1 mill certificates as standard, 3.2 with third-party inspection on request, plus dimensional and PMI reports.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026