Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Nitronic 60 Screw Conveyors - Anti-Galling Flight Service
Nitronic 60 screw conveyors (UNS S21800) flight against trough wall in continuous-conveying service. 316L flights gall against 316L trough walls within months of service in abrasive-product handling. Nitronic 60 flight against Nitronic 60 trough eliminates the scoring failure mode that retires conventional stainless conveyors early.
TorqBolt stocks Nitronic 60 (UNS S21800) at our Mumbai head office and Rajkot production plant. Each consignment ships with EN 10204 3.1 mill test certification by default and 3.2 dual-witnessed inspection (Lloyds, TUV, DNV, BV) on request. Contact info@torqbolt.com or +91-22-66157017 for sized stock and lead time.
Service Envelope for Screw Conveyors
Screw conveyor flights rotate against trough wall under sliding contact while handling product mass between flight and wall. The contact stress at the flight tip exceeds 316L's galling threshold; the flight progressively scores the trough wall and the flight tip rounds. Eventually flow efficiency degrades and the conveyor needs flight replacement. Nitronic 60 chemistry eliminates this mode.
- Continuous-conveying service: Nitronic 60 against Nitronic 60 tolerates years of service without flight wear.
- Abrasive-product handling: flight tip retains profile under abrasive load.
- Food-processing service: FDA-acceptable austenitic chemistry, sanitary-design compatible.
- Chemical-product handling: corrosion resistance comparable to 304 with anti-galling.
- Pharmaceutical service: smooth-surface finish compatible with sanitary cleaning.
Target Components in Screw Conveyors
- Flight (helical screw) machined from Nitronic 60 plate or rolled from bar.
- Trough wall plate from Nitronic 60 plate stock.
- Shaft and coupling fasteners from Nitronic 60 hex bolts / stud bolts.
- End-bearing housings with Nitronic 60 bushings.
Chemistry — UNS S21800
Cr 16-18 / Mn 7-9 / Ni 8-9 / Si 3.5-4.5 / N 0.08-0.18 / C ≤0.10. See full element ranges with single and aggregate limits →
Mechanical Properties
Yield 55 ksi (380 MPa) min, tensile 95 ksi (655 MPa) min, elongation 35% min (annealed). Hardness Rockwell B95-95 typical. See full mechanical specification with bar / forging / wire conditions →
Galling Resistance
Nitronic 60 threshold stress 50,000 psi+ per ASTM G98 vs 304/316L at 4,000-6,000 psi — 5 to 10× better galling resistance. See full ASTM G98 data and galling failure mechanism →
Heat Treatment
Solution anneal only at 1900-1950°F followed by water quench. No precipitation hardening response. See full heat treatment specification →
Welding
Matching filler ER218 per AMS 5847. GTAW, GMAW, and SMAW all qualified. No PWHT required for typical thicknesses. See full welding procedure →
Material Selection
Nitronic 60 wins for anti-galling at high temperature where 304/316L gall. Stellite is harder but brittle. vs 316L · vs Nitronic 50 · austenitic context →
Nitronic 60 Applications by Industry
- Marine and offshore, anti-galling bolting and deck hardware.
- Oil and gas, subsea wellhead, NACE MR0175 sour service, christmas-tree fasteners.
- Nuclear, valve trim, pump shafts, reactor coolant bolting.
- Food processing, FDA-acceptable austenitic, sanitary fittings, mixer paddles.
- Cryogenic, LNG hardware, austenitic stability to -196 C.
- Pump and rotating equipment, shafts and bushings under sliding seal contact.
- Valve stems, gate / globe valve stems under pressure cycling.
- Anti-galling general applications, cross-industry summary.
Related Nitronic 60 Forms and Fasteners
- Bar: round bar, hex bar, square bar, flat bar.
- Plate, sheet, forgings: plate, sheet, forgings.
- Wire and tubing: wire, spring wire, tubing, seamless pipe.
- Bolts: hex bolts, stud bolts, anchor bolts, socket head cap screws.
- Nuts: hex nuts, heavy hex nuts, lock nuts, jam nuts.
- Pins and inserts: dowel pins, clevis pins, bushings, Helicoil thread inserts.
- Catalog: full Nitronic 60 fastener portfolio, anti-galling fasteners.
Request a Quote
For Nitronic 60 hardware specified for screw conveyors, Contact the TorqBolt QA-QC team at info@torqbolt.com or +91-22-66157017. We respond within 24 hours with sized stock availability, lead time, and EN 10204 3.1 / 3.2 MTC documentation samples.
Frequently Asked Questions
Why Nitronic 60 for screw conveyors?
The anti-galling chemistry eliminates the dominant failure mode of 304 / 316L hardware in screw conveyors. Specifically the threshold galling stress per ASTM G98 is 5 to 10 times higher self-mated.
What forms are typically specified?
Fasteners (hex bolts, stud bolts, hex nuts), shafts, bushings, valve trim, sliding-contact components. See full fastener portfolio for the catalog overview.
What certification is required for screw conveyors?
Typically EN 10204 3.1 mill test certificate as standard, with 3.2 dual-witnessed inspection (Lloyds, TUV, DNV, BV) for safety-critical or regulatory-monitored components. NACE MR0175 compliance available where sour-service exposure is part of the envelope.
Alternative materials for screw conveyors?
Duplex 2205 (better chloride resistance, moderate galling), Inconel 625 (high-temperature corrosion at much higher cost), Stellite 6 (extreme galling at 15 to 25 times the cost). Nitronic 60 is the stainless-price-point anti-galling specification.
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