Standards
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175 / ISO 15156-2
- NORSOK M-650 Qualified
- API 6A Certified
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Incoloy 925 Set Screws (UNS N09925)
Headless socket-drive grub screws — cup / cone / dog / flat / oval point variants ASME B18.3 / DIN 913–916
Incoloy 925 set screws (UNS N09925), also called grub screws, are headless threaded fasteners with an internal hex socket drive (Allen) and a functional point at the working end. Set screws are designed to LOCK against another component, the point digs into a shaft surface or seats in a matching pocket, holding the assembled position against rotation or axial movement. Distinct from cap screws (which use the head as the loading surface), set screws transfer load through the POINT geometry. The five standard point types, cup, cone, dog, flat, oval, each suit different applications. Cup point (most common) digs slightly into the shaft for moderate hold; cone point penetrates deeper for permanent installation; dog point engages a matching hole or slot for positive locking; flat point is non-marring; oval point gives moderate hold without surface damage. TorqBolt manufactures Incoloy 925 set screws in M3 to M20 (#4 to 3/4") sizes ASME B18.3 (inch) / DIN 913 (flat) / DIN 914 (cone) / DIN 915 (dog) / DIN 916 (cup), in the solution-annealed and aged condition with hardness controlled within the 35 HRC NACE MR0175 sour-service cap.
Need Incoloy 925 set screws? Email info@torqbolt.com with diameter × length, point type (cup / cone / dog / flat / oval), thread series, quantity. WhatsApp +91-22-66157017.
Set Screw Variants by Point Type
| Point Type | Standard | Function |
|---|---|---|
| Cup point (most common) | DIN 916 / ISO 4029 / ASME B18.3 | Concave-cup tip with annular cutting edge; bites moderately into shaft surface; suitable for set-and-forget installation |
| Cone point | DIN 914 / ISO 4027 / ASME B18.3 | 118° tapered tip; deep penetration for permanent locking; requires matching detent on shaft |
| Dog point (full / half) | DIN 915 / ISO 4028 / ASME B18.3 | Cylindrical extension at tip; mates with hole or slot for positive position retention |
| Flat point | DIN 913 / ISO 4026 / ASME B18.3 | Flat tip; non-marring; for setting against a hardened-steel insert or pre-flat surface |
| Oval point | ASME B18.3 (no standard DIN equivalent) | Domed tip; moderate hold without surface damage; allows minor angular adjustment |
| Knurled cup point | DIN 7986 | Knurled cup tip for grip enhancement on hard shafts |
| Square-head set screw | ASME B18.6.2 (older standard) | Legacy variant with external square drive head; rare in new construction |
Standard Size Range
| Diameter | UNC | Metric Coarse | Hex Socket | Length Range |
|---|---|---|---|---|
| #4 / M3 | UNC 40 | M3 × 0.5 | 1.5 mm | 3 to 30 mm |
| #10 / M5 | UNC 24 | M5 × 0.8 | 2.5 mm | 4 to 50 mm |
| 1/4" / M6 | UNC 20 | M6 × 1.0 | 3 mm | 5 to 60 mm |
| 5/16" / M8 | UNC 18 | M8 × 1.25 | 4 mm | 6 to 80 mm |
| 3/8" / M10 | UNC 16 | M10 × 1.5 | 5 mm | 8 to 100 mm |
| 1/2" / M12 | UNC 13 | M12 × 1.75 | 6 mm | 10 to 120 mm |
| 5/8" / M16 | UNC 11 | M16 × 2.0 | 8 mm | 12 to 150 mm |
| 3/4" / M20 | UNC 10 | M20 × 2.5 | 10 mm | 15 to 180 mm |
Mechanical Properties (Aged)
Tensile 165 ksi min / Yield 110 ksi min / Hardness 32–35 HRC for sour service (NACE cap). For non-sour applications requiring spring function (e.g. spring-loaded ball detent), point hardness can be raised to 45–50 HRC by selective omission of the 8-hour age step, specify "non-NACE high-hardness" at RFQ stage if needed. See full mech properties page.
Applications
- Shaft-collar locking (rotating-machinery shaft retention), cup or cone point bites into shaft
- Hub / pulley axial-position retention, cone point in matching detent
- Bearing-cup locking in housing, flat point against hardened bearing race
- Instrument adjustment screws, oval / flat point for non-marring repeat adjustment
- Manifold port plug (with sealing washer), flat point seals against soft gasket
- Anti-rotation locking for adjacent threaded components, cup point against threaded surface
- Wellhead-internal adjustable mechanisms, sour-service NACE-compliant grub screws in valve trim
Standards
- ASTM B805, UNS N09925 forging stock
- ASME B18.3, Socket Cap, Shoulder, Set Screws (inch series)
- DIN 913 / ISO 4026, Hexagon Socket Set Screws with Flat Point
- DIN 914 / ISO 4027, Cone Point
- DIN 915 / ISO 4028, Dog Point
- DIN 916 / ISO 4029, Cup Point
- DIN 7986, Knurled Cup Point
- ASME B1.1 / B1.13M, thread series; NACE MR0175 Table A.10; EN 10204 3.1 / 3.2
Manufacturing Sequence
- Bar input per ASTM B805 in annealed condition (round bar diameter matched to set-screw nominal size)
- Cut to length + face both ends
- Hex socket broaching at one end (driving end)
- Point machining at opposite end (cup / cone / dog / flat / oval per spec)
- Continuous external thread cutting / rolling along full length (annealed condition)
- Solution anneal + age cycle per heat-treatment specification
- Final inspection: hex socket Go/No-Go, point geometry, length, thread Go/No-Go, 100% hardness
- Bagged shipment with heat number on packaging (set screws too small for individual stamping below M8)
Frequently Asked Questions
Which point type should I order? CUP point for general shaft locking (most common, default choice); CONE point for permanent installation in matching detent; DOG point for positive position retention with matching hole; FLAT point for non-marring against hardened surface; OVAL point for moderate-hold + minor angular tolerance. If unsure, specify cup point.
Can set screws be reused after removal? Cup and cone points typically deform on first installation (digging into shaft) and may not give the same hold on reinstall. Flat and oval points are reusable. For applications requiring repeated assembly / disassembly, prefer flat / oval points or use a hardened insert in the shaft.
Lead time? Standard cup-point set screws (M5 to M12 / #10 to 1/2"): 4–6 weeks. Other point types (cone, dog, flat, oval): 6–8 weeks. Sub-#4 / M3 sizes: limited supply, 8–10 weeks.
Documentation Package & Related Products
EN 10204 3.1 MTC (3.2 with TPI on request); chemistry, tensile, 100% hardness, point geometry verification, hex socket Go/No-Go, NACE MR0175 reference. Related: socket head cap screws, threaded rods, hex bolts, full datasheet.
Request a Quote
Email info@torqbolt.com · Phone +91-22-66157017 · WhatsApp +91-22-66157017. Specify point type, diameter × length, thread series, quantity, applicable standards (ASME B18.3 / DIN 913–916 / ISO 4026–4029), MTC level.
References: ASTM B805; ASME B18.3; DIN 913 / 914 / 915 / 916 / 7986; ISO 4026 / 4027 / 4028 / 4029; ASME B1.1 / B1.13M; NACE MR0175 / ISO 15156-3 Table A.10; EN 10204. INCOLOY® is a registered trademark of Special Metals Corporation.
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