DIN 916 Alloy Steel Hex Socket Set Screw with Cup Point for Marine Equipment

DIN 916 Alloy Steel Set Screw manufactured per DIN 916 / ISO 4029, headless hexagon socket set screw with cup point for positional locking of rotating and sliding components on shafts in marine machinery. Available in strength category 45H (alloy steel) and stainless steel grades A2 (AISI 304) / A4 (AISI 316) for corrosion-prone shipboard environments. Thread range M3 to M24, product grade A. The Hex Socket Set Screw cup point bites into the mating shaft surface to prevent rotation or slippage — a critical fastening method for marine gearboxes, pump couplings, and propeller shaft accessories. All Cup Point Set Screws are supplied with full material certificates and dimensional inspection reports. Products conform to DIN 916 requirements and can accommodate third-party classification society inspection.

What Is a DIN 916 Hex Socket Set Screw?

ADIN 916 Hex Socket Set Screw is a headless fastener with an internal hexagon socket drive and a cup point tip. Per DIN 916 (national adoption of ISO 4029:1977), the cup point features a sharp-edged recessed ring that bites into the mating shaft surface when tightened, creating a permanent positional lock. The 120° cone angle at the tip transition and approximately 45° transition from thread root to cup point diameter ensure reliable grip without requiring a drilled or spotted seat — making it the most versatile general-purpose set screw for marine mechanical assemblies.

The headless design allows the screw to sit entirely below the component surface, which is essential in marine applications where protruding fastener heads would interfere with rotating parts, create flow turbulence, or prevent proper seating of couplings and bearings. The hexagon socket drive provides high torque transmission in confined spaces where external wrench access is limited — typical in ship engine rooms and pump compartments.

Material and strength options per DIN 916:

• Steel, Category 45H — Alloy steel, hardness 45HRC equivalent; standard for high-strength mechanical locking. Surface finish: black oxide (thermally or chemically blackened per DIN 267 Part 1). Thread tolerance: 5g6g.
• A2 (AISI 304) Stainless Steel — A2-70 for sizes ≤ M20, A2-50 for sizes > M20. For general marine humid environments.
• A4 (AISI 316) Stainless Steel — A4-70 for sizes ≤ M20. For seawater-exposed and high-chloride applications.

Marine Applications

Note: The following applications are based on typical industry practice for DIN 916 cup point set screws in marine and offshore environments. Material grade selection should consider exposure conditions, load type, and maintenance accessibility.

Specifications & Materials

Key Dimensions by Thread Size (selected sizes)

Note: Socket depth t has two values — short screw / long screw. All dimensions per DIN 916:1980, Table 1.

Why Choose sinofastener for DIN 916 Set Screws?

Standards Reference

FAQ

Q1: What is the difference between DIN 916 cup point and DIN 913 flat point set screws?

A: DIN 916 cup point set screws have a recessed sharp-edged ring tip that bites into the shaft surface for strong permanent grip — ideal for locking gears, pulleys, and couplings against rotation. DIN 913 flat point set screws distribute force over a larger area and leave minimal marking on the shaft — preferred when components need frequent adjustment or repositioning. For marine applications where vibration resistance is critical, DIN 916 cup point is the standard choice.

Q2: Which material should I use for seawater-exposed set screws?

A: A4 grade (AISI 316 stainless steel) is recommended for all set screws exposed to seawater or salt spray. AISI 316 contains 2–3% molybdenum which provides superior resistance to pitting and crevice corrosion in chloride environments. For enclosed engine room applications with no direct water exposure, alloy steel 45H with black oxide finish offers higher strength at lower cost.

Q3: What hex key size fits a DIN 916 M12 set screw?

A: A 6 mm hexagon key. Standard socket sizes per DIN 916: M3=1.5mm, M4=2mm, M5=2.5mm, M6=3mm, M8=4mm, M10=5mm, M12=6mm, M16=8mm, M20=10mm, M24=12mm.

Q4: Can you supply DIN 916 set screws with classification society certificates?

A: Yes. Our products conform to DIN 916 requirements and we supply material certificates per EN 10204 (3.1 standard, 3.2 on request). Third-party inspection by classification societies (DNV, ABS, LR, CCS, BV) can be arranged upon request.