Nitronic 60 Socket Cap Screws Specification

NITRONIC 60 Equivalent Designation
| UNS Designation | British STD | Werkstoff No. | European STD | Swedish STD | Japanese STD |
|---|---|---|---|---|---|
| S21800 | – | – | – | – | – |
Nitronic 60 Socket Cap screws are externally threaded fasteners typically driven into a tapped hole or self-tapped material. TorqBolt manufactures Nitronic 60 Socket Cap screws per ASME B18.3 (socket products), ASME B18.6.3 (machine screws), DIN 912 / 7991 / 6912, and ISO 4762 / 10642, in metric M3–M48 and imperial 0–1/2".
Nitronic 60 Socket Cap screws are available in cap (cylindrical), button (low-profile dome), countersunk / flat (82° or 90°), pan, fillister, truss, and shoulder configurations. Countersunk per DIN 7991 with 90° head angle is standard for metric; 82° per ASME B18.6.3 for imperial.
Nitronic 60 Socket Cap screws use full-thread or partial-thread (length-under-head) configurations. Machine screws are typically full-thread; cap screws use partial thread for grip control. Threading per ASME B1.1 (UNC/UNF) or ISO 965 (metric coarse/fine), Class 2A or 6g default. Length-under-head is measured from the bearing surface for hex/cap, from the largest face for countersunk. Custom lengths quoted to drawing.
TorqBolt produces Nitronic 60 Socket Cap set screws (cup-point, cone-point, dog-point, flat-point, hex-socket DIN 913/914/915/916), shoulder screws (precision-ground shoulder for pivot applications), and self-tapping screws (Type AB, Type 25). All certified per EN 10204 3.1 / 3.2 with optional NACE MR0175 sour-service compliance.
Nitronic stainless steels are nitrogen-strengthened austenitic alloys that achieve high yield strength (1.5-2× conventional 304/316) without the heat-treatment required for precipitation-hardening grades. Nitrogen acts as a powerful interstitial solid-solution strengthener while remaining fully austenitic, retaining the corrosion resistance and toughness of standard austenitics.
Nitronic 50 (UNS S20910) is the dominant grade: 22Cr-13Ni-5Mn-2Mo-0.3N giving yield ~380 MPa in the annealed condition (vs ~205 MPa for 316L) and corrosion resistance better than 316L. The standard choice for high-strength corrosion-resistant fasteners in marine + chemical-process service. Nitronic 60 (S21800) trades some corrosion for outstanding galling and wear resistance — the workhorse for valve trim, threaded couplings, and wear-prone bolting where galling would destroy a 304/316 thread. Nitronic 32 / 33 / 40 are low-Ni variants for cost-sensitive applications.
Nitronic fasteners ship per ASTM A276 / A479 with EN 10204 3.1 / 3.2 certification covering nitrogen content (critical for property reproducibility), tensile, hardness, and stress-corrosion testing. NACE MR0175 sour-service is fully qualified in the annealed condition for both Nitronic 50 and 60.