Metric A2 Stainless Steel Knurled Point Set Screws
Metric Knurled Point Set Screws in A2 (18-8) Stainless Steel—also called serrated point set screws, knurled cup point set screws, knurl point grub screws, or diamond point set screws—feature a textured, cross-hatched serrated tip that provides excellent holding power while allowing for repositioning and adjustment. The knurled pattern creates multiple small contact points that bite into the shaft or mating surface, distributing grip across a broader area than a standard cup point edge. This design offers a practical balance between secure fastening and serviceability, making knurled point set screws ideal for applications requiring periodic adjustment, alignment tweaking, or component repositioning without excessive shaft damage.
How Knurled Point Set Screws Work
The knurled point features a diamond or cross-hatch pattern machined into the tip of the set screw. When tightened against a shaft or workpiece, the raised edges of the knurl pattern dig into the mating surface, creating friction and mechanical resistance to rotation. Unlike a cup point that concentrates force along a single circular edge, the knurled point spreads contact across many small peaks, resulting in a secure grip with more moderate surface indentation. This allows the set screw to be loosened, the component repositioned, and the screw retightened in a slightly different location—often multiple times—before shaft damage becomes significant enough to affect holding power.
Why Choose Knurled Point Over Other Point Styles?
Selecting the correct set screw point style depends on balancing holding power, surface damage, and adjustability:
- Knurled Point: Good holding power with moderate shaft marking—best for applications requiring occasional repositioning or adjustment while maintaining secure grip between adjustments
- Cup Point: Excellent holding power with significant shaft marking—best for semi-permanent installations where maximum grip is needed and shaft damage is acceptable
- Cone Point: Maximum holding power with permanent shaft damage—best for permanent installations with a mating indentation
- Flat Point: Minimal holding power with no shaft damage—best for frequent adjustment against hardened surfaces or when shaft protection is critical
- Oval Point: Low holding power with minimal shaft damage—best for frequent adjustment applications, often used with a shaft groove
- Dog Point: Positive mechanical engagement—best for precise alignment into a mating hole or keyway
Knurled point set screws occupy the middle ground between cup point aggression and flat point gentleness, making them versatile fasteners for applications where requirements may change or where fine-tuning is part of normal operation.
Why Choose A2 (18-8) Stainless Steel?
A2 stainless steel—also known as 18-8 or 304 stainless—is the most widely used stainless steel grade for fasteners worldwide. The designation "18-8" refers to the approximate composition: 18% chromium and 8% nickel. This combination creates a passive oxide layer on the surface that provides excellent resistance to corrosion, rust, and staining in most atmospheric conditions and many chemical environments. A2 stainless steel is non-magnetic in the annealed condition and offers good strength for general-purpose fastening applications. For set screws, A2 stainless provides reliable performance in environments where carbon steel or alloy steel would corrode, while the knurled point maintains effective grip even without the extreme hardness of heat-treated alloy steel.
Knurled Point in Stainless Steel Applications
The combination of knurled point and A2 stainless steel is particularly well-suited for applications requiring both corrosion resistance and adjustability. In food processing, pharmaceutical, and medical equipment, components often need repositioning during setup, changeover, or maintenance—knurled point set screws allow this adjustment while resisting loosening during operation. In marine, outdoor, and wet environments, stainless steel prevents rust and staining while the knurled tip maintains grip even if the fastener must be removed and reinstalled during service. The moderate shaft marking characteristic of knurled points also aligns well with the softer materials often found in stainless steel assemblies, such as aluminum shafts and components.
Material Properties & Specifications
Our metric A2 stainless steel knurled point set screws are manufactured to metric sizing standards with internal hex (Allen) socket drive for flush installation. A2 stainless steel provides a minimum tensile strength of approximately 500-700 MPa (70,000-100,000 PSI) depending on size—suitable for most general-purpose applications. The knurled point is machined to create consistent diamond-pattern serrations that provide reliable grip across the full range of recommended torque values. A2 stainless performs well in temperatures ranging from cryogenic up to approximately 800°F (425°C) for intermittent exposure.
A2 vs. A4 Stainless Steel
Both A2 and A4 are austenitic stainless steels offering excellent corrosion resistance, but they differ in specific capabilities. A2 (18-8 / 304) provides excellent corrosion resistance for most environments and is the standard choice for general-purpose stainless fasteners at economical pricing. A4 (316) contains added molybdenum, providing superior resistance to chlorides, salt water, and aggressive chemical environments—but at higher cost. Choose A2 for general corrosion resistance in most applications; choose A4 for marine, coastal, swimming pool, chemical processing, or high-chloride environments where maximum corrosion resistance is essential.
Common Applications
Metric A2 stainless steel knurled point set screws are specified across industries where corrosion resistance and adjustability are both required:
- Food & Beverage Processing: Adjustable guides, conveyor components, mixer assemblies, packaging equipment requiring frequent changeover
- Medical & Laboratory: Instrument assemblies, adjustable fixtures, equipment requiring periodic calibration or repositioning
- Marine & Outdoor: Deck hardware, adjustable mounts, equipment exposed to moisture and salt air
- Electronics & Instrumentation: Enclosure assemblies, adjustable brackets, sensor mounts, control panel hardware
- Machinery & Automation: Adjustable stops, position indicators, components requiring setup adjustment
- General Industrial: Any application requiring secure fastening with occasional repositioning in corrosive environments
Installation Tips
For optimal holding power, ensure the shaft or mating surface is clean and free of oil, grease, or debris before tightening. Use the correct size hex key (Allen wrench) and tighten to manufacturer-recommended torque specifications—over-tightening can strip threads or cause excessive shaft damage, while under-tightening may allow slippage. When repositioning, slightly rotate the component so the knurled point engages fresh material rather than seating in previous indentations. Stainless steel can gall when threaded against other stainless components—consider using anti-seize compound on threads when installing into stainless tapped holes.
Available Sizes
We stock metric A2 stainless steel knurled point set screws in a range of popular thread sizes and lengths to cover most adjustment and positioning applications. Albany County Fasteners offers competitive bulk pricing and same-day shipping on in-stock items.
Need alloy steel, a different point style, or a specific size? Contact our team—with over 18 million fasteners in stock, we can help you source the right set screw for your application.