What sizes and materials are supplied?

ISK-08 through ISK-36, covering M8 to M36, in carbon and stainless variants with a design envelope of -196 °C to +650 °C depending on variant. Material, coating and surface finish are specified per order.

Can ISOKLAMP analyse my joint before I order?

Yes. Send the bolt size and property class, target preload, what the joint clamps and how it is loaded. We return a joint-specific VDI 2230 Sheet 1 estimate and a rotational / non-rotational diagnosis, and we will say plainly when a wedge washer or a disc spring is the better answer.

Contact sales

Tell us about the joint that keeps failing. We size the washer against it, quote the sizes and materials you need, and set a supply schedule against your build dates. Sizes M8 to M36, carbon and stainless variants, specified per order.

What you get

A joint-specific VDI 2230 analysis and a rotational / non-rotational diagnosis of the target joint. A quotation against your size, material, coating and volume. A DIN 25201-4 Annex B series run at your duty cycle where your specification calls for it, with the report issued in your name. Supply scheduled against your build dates.

What we need from you

Bolt size and property class, target preload or tightening torque, what the joint clamps, the loading and thermal duty, and what has been tried so far. Maintenance history helps if you have it.

Sector application support

Hygienic process, busbar and battery, hydrogen and cryogenic, composite structure and nuclear each carry their own constraints on surface finish, material and inspection. Say which one you are in and the analysis comes back framed against those constraints.

What the evidence says

Real, citable, third-party material on how bolted joints lose clamp force. For this audience it is more useful than a quotation, and unlike a quotation it can be verified.

“Safety devices principally intended to resist rotational loosening and prevent loss of fasteners.”
NASA-STD-5020, defining what a locking feature is for. Note what it does not say.

“Testing in accordance with this International Standard does not allow an absolute statement to be made on the locking behaviour of bolted assemblies under service loads.”
ISO 16130:2015, scope clause.

“41 % of preload lost in the first 20 → 120 °C thermal cycle, with nut rotation of order 5 × 10⁻⁴ degrees.”
Eraliev, Zhang, Lee & Lee, Advances in Mechanical Engineering 13(8), 2021.

“10 to 40 % of preload lost to cyclic plastic ratcheting within 200 load cycles, with no measurable nut rotation.”
Jiang, Zhang & Lee, ASME Journal of Mechanical Design 125(3), 2003.

“All prestress lost within one week at 240–260 °C; bolts removable by hand.”
Jaglinski & Lakes, aluminium engine-block joints, 2007.

“Flight joints lost more than 40 % of preload over a five-year extrapolation without re-torque. A single re-torque 24 hours after installation halved the loss.”
NASA JWST heat-strap study, ESMATS 2018.

Send a sales enquiry

Questions

What sizes and materials are supplied?: ISK-08 through ISK-36, covering M8 to M36, in carbon and stainless variants with a design envelope of -196 °C to +650 °C depending on variant. Material, coating and surface finish are specified per order.
Can ISOKLAMP analyse my joint before I order?: Yes. Send the bolt size and property class, target preload, what the joint clamps and how it is loaded. We return a joint-specific VDI 2230 Sheet 1 estimate and a rotational / non-rotational diagnosis, and we will say plainly when a wedge washer or a disc spring is the better answer.