The primary duty of Fine-Thread Hex Flange Bolts, Small Series is a fine-pitch hex bolt with an integral flange, in the small series whose head fits tighter wrench clearances. Below: the sectors that specify them in volume, the checklist used to select the right size and material for the application, installation notes, and the known limits of the type. Stocked across roughly M8 to M16, they cover general to heavy-duty work.
Typical Applications for Fine-Thread Hex Flange Bolts, Small Series
The most common settings where these are specified:
- Automotive powertrain: oil pans, covers and brackets with fine-thread tapped holes.
- Hydraulic equipment: pump and valve bodies where fine threads hold in thin walls.
- Motorcycle assembly: engine covers with limited socket clearance.
- Machinery guarding: flanged fixings that spread load on thin sheet.
How to Specify Fine-Thread Hex Flange Bolts, Small Series for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans M8–M16; check the full table below for the exact dimensions of each size.
- Strength class: Choose the property class (e.g. 8.8, 10.9, 12.9 or A2/A4 stainless) for the load and environment, and tighten to the matching torque so the joint relies on preload, not friction.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to ISO 15072. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Installation & Assembly Practice
- Tighten to the torque for the size and property class with a calibrated wrench — the joint is held by preload, not by the thread friction alone.
- Ensure at least one full thread projects beyond the nut after tightening, and never re-use a bolt that has been tightened into yield.
- Under slotted or oversized holes, fit a hardened washer so the preload does not relax into the hole edge.
Common Selection Mistakes with Fine-Thread Hex Flange Bolts, Small Series
- Specifying class 12.9 "to be safe" in a corrosive environment — high classes are more sensitive to hydrogen embrittlement and stress corrosion; 8.8 hot-dip galvanized often outlasts them outdoors.
- Choosing a length that puts the shear plane through the threaded portion when a plain shank (partially threaded bolt) was available.
- Mixing stainless bolts with plated-steel nuts: the joint loses its corrosion logic and can gall or seize.
Where Fine-Thread Hex Flange Bolts, Small Series Are Not the Right Choice
Not for permanent joints that will never be opened (a rivet or weld is cheaper), and not where the head must sit flush — use a countersunk screw instead.
Custom manufacturing · Made to drawing
Need a fine-thread hex flange bolts, small series outside the standard range?
Where the standard stops, the drawing takes over: fine pitches, left-hand threads, partial threading, and property classes above the catalogued grade where material and heat treatment allow. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
