DIN 913 / ISO 4026 Socket Set Screw with Flat Point A2 Stainless

DIN 913 / ISO 4026 — Socket Set Screw with Flat Point | A2 Stainless Steel

FULLERKREG DIN 913 / ISO 4026 socket set screws (grub screws) with flat point are manufactured to full DIN and ISO dimensional standards in A2 stainless steel (SUS 304) with a bright passivated surface finish. Designed for secure, non-marring clamping and positioning applications where the flat point distributes load evenly without penetrating or damaging the mating surface.

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Product Specifications

Parameter	Detail
Standard	DIN 913 / ISO 4026
Type	Socket Set Screw (Grub Screw) — Flat Point
Drive	Hexagon Socket (Hex Allen Key)
Material	A2 Stainless Steel (SUS 304 / 1.4305)
Surface Treatment	Bright Passivated (Electrochemical Passivation)
Thread	Metric Coarse Thread (ISO 68-1)
Thread Tolerance	6H (internal) / 6g (external) per ISO 965
Property Class	A2-70 (per ISO 3506-3)
Size Range	M1.6 — M24
Length Range	2 mm — 60 mm (size-dependent)
Point Type	Flat Point
Head Type	Fully Threaded, Headless (Grub)
RoHS Compliant	Yes

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Key Dimensions (DIN 913 / ISO 4026)

Thread (d)	Hex Key Size (s)	Min. Thread Engagement	Flat Point Dia. (dp) approx.	Common Lengths
M1.6	0.7 mm	0.8 mm	0.80 mm	2, 3, 4, 5 mm
M2	0.9 mm	1.0 mm	1.00 mm	2, 3, 4, 5, 6 mm
M2.5	1.3 mm	1.25 mm	1.50 mm	3, 4, 5, 6, 8 mm
M3	1.5 mm	1.5 mm	2.00 mm	3, 4, 5, 6, 8, 10 mm
M4	2.0 mm	2.0 mm	2.50 mm	4, 5, 6, 8, 10, 12 mm
M5	2.5 mm	2.5 mm	3.50 mm	5, 6, 8, 10, 12, 16 mm
M6	3.0 mm	3.0 mm	4.00 mm	6, 8, 10, 12, 16, 20 mm
M8	4.0 mm	4.0 mm	5.50 mm	8, 10, 12, 16, 20, 25 mm
M10	5.0 mm	5.0 mm	7.00 mm	10, 12, 16, 20, 25, 30 mm
M12	6.0 mm	6.0 mm	8.50 mm	12, 16, 20, 25, 30, 40 mm
M16	8.0 mm	8.0 mm	12.00 mm	16, 20, 25, 30, 40, 50 mm
M20	10.0 mm	10.0 mm	15.00 mm	20, 25, 30, 40, 50, 60 mm
M24	12.0 mm	12.0 mm	18.00 mm	25, 30, 40, 50, 60 mm

All dimensions per DIN 913 / ISO 4026. Consult FULLERKREG datasheet or contact us for full tolerance tables.

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Material & Surface Finish

A2 Stainless Steel (SUS 304)

• Composition: 18% Chromium, 8–10% Nickel, ≤0.08% Carbon (austenitic stainless steel)
• Corrosion Resistance: Excellent resistance to atmospheric corrosion, mild acids, and most organic chemicals
• Magnetic: Non-magnetic in annealed state; may become slightly magnetic after cold working
• Temperature Range: Suitable for −196°C to +300°C continuous service
• Tensile Strength: Min. 700 MPa (A2-70 per ISO 3506-3)
• Proof Load Stress: Min. 450 MPa
• Hardness: Max. 220 HV (Vickers)

Bright Passivated Surface Finish

• Electrochemical passivation removes free iron and surface contaminants from the stainless steel surface
• Restores and enhances the natural chromium oxide passive layer for maximum corrosion resistance
• Produces a bright, clean, silver appearance — no coating thickness added, no dimensional change
• Compliant with ASTM A967 / ISO 16048 passivation standards
• No risk of hydrogen embrittlement (no electroplating involved)

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Flat Point — Design & Function

The flat point is the most versatile set screw tip geometry. It provides a broad, flat contact surface against the mating shaft or component, making it ideal for:

• Non-marring clamping — does not indent or damage polished or soft shafts
• Frequent adjustment — can be loosened and repositioned without leaving permanent marks
• Hardened shafts — distributes clamping force over a larger area, reducing point stress
• Thin-walled components — lower risk of deformation compared to cup or cone points
• Locking against rotation — friction-based holding when tightened against a flat on the shaft

Flat Point vs. Other Set Screw Point Types

Point Type	Standard	Best For	Shaft Marking
Flat Point	DIN 913 / ISO 4026	Non-marring, frequent adjustment, hardened shafts	None / Minimal
Cup Point	DIN 916 / ISO 4029	Permanent locking, soft shafts, high torque	Circular indent
Cone Point	DIN 914 / ISO 4027	Permanent location, V-groove shafts	Deep indent
Dog Point	DIN 915 / ISO 4028	Precise location, keyway-free shafts	None (pin engagement)
Oval Point	ISO 4026 variant	Curved surfaces, pivot points	Minimal

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Typical Applications

• Securing pulleys, gears, cams, and collars to shafts in machinery
• Positioning components in optical, medical, and laboratory instruments
• Locking set positions in food processing and pharmaceutical equipment (A2 stainless preferred for hygiene)
• Electronics and automation assemblies requiring non-magnetic fasteners
• Marine and outdoor equipment exposed to moisture and mild corrosives
• Adjustable mechanical stops and travel limiters
• Clamping knobs, handles, and handwheels to shafts

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Installation Guidelines

• Thread engagement: Minimum engagement length = 1× nominal diameter (e.g., M6 requires min. 6 mm engagement)
• Tightening torque: Use a calibrated torque wrench; refer to ISO 898-1 / ISO 3506 torque tables for A2-70
• Lubrication: Apply anti-galling compound (e.g., molybdenum disulfide paste) to prevent thread galling on stainless-to-stainless assemblies
• Hex key: Use the correct size hex key (Allen key) — see dimension table above; worn keys risk cam-out and socket damage
• Shaft flat: For maximum holding power, machine a flat on the shaft at the set screw contact point
• Locking: For vibration-prone applications, use thread-locking adhesive (medium strength) or nylon patch set screws
• Do not over-torque: Stainless steel has lower hardness than alloy steel; over-torquing risks thread stripping or socket rounding

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Recommended Tightening Torques (A2-70, Dry)

Thread	Torque (N·m) — Reference
M2	0.08 N·m
M2.5	0.17 N·m
M3	0.30 N·m
M4	0.70 N·m
M5	1.40 N·m
M6	2.40 N·m
M8	5.80 N·m
M10	11.5 N·m
M12	20.0 N·m
M16	49.0 N·m
M20	96.0 N·m

Reference values for dry, unlubricated A2-70 stainless. Reduce by 15–20% when using lubricant or anti-galling compound. Always verify with your engineering team for safety-critical applications.

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Standards & Compliance

• DIN 913 — Socket set screws with hexagon socket and flat point
• ISO 4026 — Hexagon socket set screws with flat point
• ISO 3506-3 — Mechanical properties of corrosion-resistant stainless steel fasteners (set screws)
• DIN 267-11 — Technical delivery conditions for fasteners; stainless steel property classes
• ISO 965-1 — Metric screw thread tolerances
• ASTM A967 / ISO 16048 — Passivation of stainless steel
• RoHS 2011/65/EU — Restriction of hazardous substances compliant

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Packaging & Ordering

• Available in standard retail packs, engineering bulk packs, and full-box quantities
• Custom quantity packaging available for OEM and wholesale customers
• Each pack labeled with: Part number, Thread size × Length, Material (A2), Standard (DIN 913 / ISO 4026), Quantity
• Bulk orders: contact FULLERKREG for volume pricing and lead times

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Quality Assurance

• 100% dimensional inspection on critical sizes per DIN 913 / ISO 4026
• Material certification (Mill Test Certificate) available on request
• Hardness and tensile testing per ISO 3506-3 batch requirements
• Thread gauge inspection (Go/No-Go) per ISO 965
• Salt spray corrosion testing available for qualification batches
• Traceability: heat number and batch records maintained

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Frequently Asked Questions

Q: What is the difference between DIN 913 and ISO 4026?
A: DIN 913 and ISO 4026 are technically equivalent standards for socket set screws with flat point. DIN 913 is the German standard; ISO 4026 is the international equivalent. Dimensions and tolerances are identical — parts are fully interchangeable.

Q: Can A2 stainless set screws be used in saltwater or marine environments?
A: A2 (304) stainless offers good general corrosion resistance but is not recommended for prolonged immersion in chloride-rich (saltwater) environments. For marine or coastal applications, A4 (316) stainless is preferred. Contact FULLERKREG for A4 options.

Q: Will the flat point damage my shaft?
A: The flat point is specifically designed to minimize shaft damage. It distributes clamping force over a broad area rather than concentrating it at a point. For polished or precision shafts, the flat point is the recommended choice.

Q: What hex key (Allen key) size do I need?
A: Refer to the dimension table above. Examples: M3 requires a 1.5 mm hex key; M6 requires a 3.0 mm hex key; M10 requires a 5.0 mm hex key.

Q: How do I prevent galling when installing stainless set screws?
A: Apply a small amount of anti-galling lubricant (molybdenum disulfide paste or copper-based anti-seize) to the threads before installation. Avoid over-torquing and use a calibrated torque wrench.

Q: Are these RoHS compliant?
A: Yes. FULLERKREG A2 stainless set screws are manufactured without restricted hazardous substances and are RoHS 2011/65/EU compliant.

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FULLERKREG — Precision Fasteners to DIN / ISO Standards. For technical support, custom sizes, or bulk quotations, please contact our engineering team.