Silicon Bronze 651 Allen Screws manufactured at TorqBolt are corrosion resistant with excellent hot and cold formability at high temperatures.
Dimensional standards as per ANSI B18.3 ,B18.3.1M.DIN 912,DIN 6912,DIN 7984,ANSI B18.3,ISO 4762,UNI 5931,BS 2470,BS 4194 are provided.
The raw material of these fasteners is classified as Non-Ferrous Alloys. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. Silicon Bronze 651 Allen Screws are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
Silicon Bronze 651 Allen Screws — Specifications & Dimensions
Silicon Bronze 651 Allen screws are externally threaded fasteners typically driven into a tapped hole or self-tapped material. TorqBolt manufactures Silicon Bronze 651 Allen 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".
Drive Types
Hex socket (Allen) — ASME B18.3 / DIN 912, primary for high-torque industrial use
Silicon Bronze 651 Allen 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.
Thread & Length
Silicon Bronze 651 Allen 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.
Specialty Screws
TorqBolt produces Silicon Bronze 651 Allen 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.
Bronze alloys are copper-based alloys with tin, aluminium, silicon, manganese, or phosphorus alloying additions, each tuned for a specific tribological or environmental envelope. Bronzes deliver excellent bearing properties, marine corrosion resistance, and non-sparking + non-magnetic characteristics — specified for marine fasteners, electrical hardware, oil + gas wellhead components, and industries where sparks must be avoided.
Phosphor bronze (Cu-Sn-P, e.g. C51000, C52400) combines high yield strength + fatigue with seawater corrosion resistance — the standard for marine + spring fasteners. Silicon bronze (Cu-Si, e.g. C65500) is the marine-grade weldable alloy popular for boat fasteners and architectural cladding. Aluminium bronze (Cu-Al, e.g. C95400/C95500/C95800) achieves yield ~310-585 MPa with outstanding seawater + cavitation resistance — the workhorse for marine pump impellers and propeller hub bolting. Gunmetal (Cu-Sn-Zn-Pb, e.g. C90500) is the historic naval bronze for valves and trim. Leaded bronze adds Pb for free-machining + bearing applications.
Bronze fasteners ship per ASTM B98 (rod/bar) and B584 (sand cast) with EN 10204 3.1 / 3.2 certificates covering composition, hardness, and ASTM B66 ammonia stress-corrosion testing where service exposure warrants.
