Rivet bushes provide strong load bearing threads

Edited by the Engineeringtalk editorial team Aug 1, 2005

The ability of rivet bushes to generate strong and permanent load bearing threads in thin sheet metal can generate both financial and "manufacturability" advantages over other types of fasteners.

The ability of rivet bushes to generate strong and permanent load bearing threads in thin (down to 0.5mm) sheet metal can generate both financial and "manufacturability" advantages over other types of captivated fasteners like, say, self-clinching fasteners or sheets nuts, in material that is otherwise too thin to be drilled and tapped for component attachment.

According to Steve Smith, Sales Director of Northern Precision, because rivet bushes are ideally suited to thin panels of any hardness (unlike self-clinching fasteners that have minimum panel thickness and maximum hardness limitations) they allow users to often reduce manufacturing costs by using thinner panels, where appropriate.

In addition, production processes can be streamlined and made more cost-effective because the need for loose nuts and washers is eliminated - along with their associated assembly times and costs.

In addition to providing excellent torque and pull-out performance, other benefits include: the price of rivet bushes compares favourably with other types of captivated fasteners; a flush finish (when using an appropriate profiled anvil) is produced on the reverse side of the panel; and rivet bushes can be installed before or after painting.

With all these advantages, it's no surprise therefore that rivet bushes are increasingly finding widespread appeal throughout the white goods, electronics enclosure, medical, catering, automotive and defence sectors - indeed, in any sheet metal fabrication application that requires a captivated thread.

Installation is simple: the item can be installed using a hydraulic or fly press - even a hammer - though for best performance a hydraulic press with suitably profiled punches is recommended.

Rivet bushes work by having an internally profiled "spigot" that protrudes through the panel just enough to allow for peening over.

They are available in a range of standard thread sizes to suit specific panel thicknesses as well as a number of head styles - for instance, round, hexagon, mini and closed end (tank style) round and mini standoffs.

Round and mini rivet bushes and rivet bush standoffs are available with knurling either on the spigot or under the body.

Northern Precision's wide range of standard rivet bushes is available in a wide range of materials (plated and unplated steel, different grades of stainless, aluminium and brass) and can be supplied next-day, or specials can be quickly produced to customer specification.

The standard range - which covers panel thicknesses up to 3mm thick (10 SWG), and quantities from 100-off to in excess of a million pieces can be supplied - comprises the following types.

The standard round knurled shoulder, in which the shoulder knurling provides excellent resistance to torque in all materials.

The standard round serrated spigot is dimensionally the same but with a serrated spigot.

This provides good resistance to torque, especially in softer materials such as aluminium.

The round mini rivet bush provides good resistance to torque in limited space.

The hexagon rivet bush provides excellent resistance to torque in all materials.

For applications requiring higher than normal bolt tightening loads, a spanner can be used on the bush.

Finally, the tank type rivet bush is closed-ended for applications where the component needs to be sealed against the ingress of air, liquid or dirt or where the incursion of an extra long thread could be potentially damaging, ie fuel and heating systems and electrical enclosures.