Forged Nuts & Special Nuts
A nut must be stronger than the bolt it holds, or it strips before the bolt reaches its rated load. That single requirement drives nut property class selection.
Forged nuts must match the property class of their bolt — class 8 with 8.8, class 10 with 10.9, class 12 with 12.9 — or the threads strip before the bolt develops its designed preload. Sizes run M8 to M64 in hex, heavy hex, castle, slotted and flange types.
- Sizes
- M8 – M64
- Property classes
- 8, 10, 12
- Types
- Hex, heavy hex, castle, slotted, flange
- Threads
- Metric, BSW, UNC, UNF
- Finish
- Plain, zinc, HDG, phosphate
Forged Nuts & Special Nuts at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Property class must match the bolt
- Sizes M8 to M64
- Hex, heavy hex, castle, slotted and flange types
- Proof load tested per property class
Property Class Matching
A class 8 nut pairs with a class 8.8 bolt, class 10 with 10.9, class 12 with 12.9. Mismatch means the threads strip before the bolt develops its designed preload — a failure mode that looks like a bolt problem but is a nut specification error.
- Class 8 nut for 8.8 bolt
- Class 10 nut for 10.9 bolt
- Mismatch strips threads early
- Proof load tested per class
Special and Locking Types
Castle and slotted nuts take a split pin for positive locking. Flange nuts spread bearing load. Cap nuts protect exposed threads. Drawing-specific nuts that no catalogue carries are made to order from 500 pieces.
People also ask
What happens if I use a lower class nut?
The nut threads strip before the bolt reaches its rated preload, so the joint fails at a fraction of its design capacity. It presents as a bolt failure but is a nut specification error.
What is a castle nut used for?
Positive mechanical locking with a split pin through slots in the nut and a hole in the bolt, used where vibration would loosen a plain nut and loosening is unacceptable.
Can you supply nuts and bolts as matched sets?
Yes, matched and property-class-verified sets with test reports covering both components.
Topics covered on this page
- forged nut
- heavy hex nut
- castle nut
- property class
- proof load
- thread stripping
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
Which nut class should I use with a 10.9 bolt?
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A class 10 nut. Using a lower class means the nut threads strip before the bolt reaches its designed preload.
Do you make non-standard nuts?
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Yes, drawing-specific nuts from 500 pieces, including castle, slotted, flange and cap types.
Are nuts proof load tested?
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Yes, to the load specified for their property class, with results reported per batch.