Thread: Making Bolt Vices

This is pretty simple and quite short....

A BOLT VICE is a simple 1 or 2 or more screw VICE, that is used to mainly hold timber while carving it or clamping a glued joint etc.

This model has 2 x 8" coach bolts - with 2 nuts per bolt, and 2 washers per bolt,

ONE big piece of wood sawn length ways in two (or similar)

A centering mark gouged in the front ; and

TWO strips of cloth reinforced THIN rubber strips.

I had to make a "Bolt Vice" so I could carve up some timber sections - from near on eye level - while seated - from the side.

So it's just made for holding wooden parts or blanks - up to about 60mm (2 -1/2") thick.

The sizes of the finished parts can be varied and they can be mounted in a vice or bolted to the bench top.... it's your call.

The advantage of this design is that it's strong enough to do the job of HOLDING the wood while it gets carved with a chisel and small rubber mallet.


Most wood clamps are not strong enough and most "metal" vices lack the "above the deck" or ability to hold BIG pieces of timber horizontally.

OK the finer details of the construction.

With timber, one needs WIDE bearing surfaces to distribute the compressive forces of the bolts onto a large area of wood - otherwise the HEX heads or nuts pull into the timber.

Coach head bolts have a large head on them - relative to hex heads....but hex heads are fine too - but they need BIG washers under them;

The only advantages to coach head bolts are that the heads have a LARGE bearing area, they are a shallow dome AND the coach bolts have a square locking key under the head that pulls into the timber and allows the bolt to be tightened from one side only with only one spanner.

The 2 nut system - being that ONE nut is used to clamp the jaws together, the second nuts are glued onto the end of the bolt thread with clear nail polish to perform the functions of protecting the thread, and protecting the user from the sharp(ish) ends of the bolts.

The rubber strips between the jaws and the work are only for grip.

I machined up some curtain rod tube into a wad cutting punch and then popped a few holes in the rubber strips to make the strips stay in position - within the assembly.

The "gouged in" centering mark is simply an easy visual guide to encourage the centering of the jobs in the bolt vice

To make the jaws you need wood - that IS free of knots and weakness's in the grain, as the timber is under tension.

I used plain radiata pine - it's perfectly servicable wood; the real issue is that these types of vices or clamps ONLY need to hold the wood being carved in position.

On a small bolt vice with narrow (ish) jaws the wood being carved will wiggle around a little bit, but it won't slide around or out of the bolt vice.


The amount of tension or clamping force ONLY needs to be high enough to hold the timber, these vices are NOT designed to carry or transmit LARGE forces of compression on any object for 2 main reasons.

1. The bolts are a "soft" steel and the thread form is of a triangular section - and as such it had limited load carrying capacity. If it is tightened hard enough, enough times, especially without any lubricant or without any anti-seize lubricant - the threads will gall or deform and shear under plastic flow.

REAL metal working vices have a much harder and stronger thread - that is generally a SQUARE form or ACME thread.

These threads are designed to carry HUGE loads..Not so with the coach bolts and the triangular threads.

2. The bolts are pulling on timber, and depending on the wood type, the thickness and width and the span of the wood; the wooden jaws will split and ruin the rubber strips and then deform and or crack and or break under very high loads.


So again - a bolt vices principle attraction is the ease of manufacturing from most ready made sources of parts; and it's designed to HOLD or restrain things; or components that are too thick or wide or deep to be held by conventional clamps - or to hold them in positions that are not available with the current clamping system.

The idea with the double washers under the nuts, is to provide extra slip between the nut and the timber - tho the nut, thread and the washers should be lubricated with anti-seize, to provide an almost indefinite life span - in a dust free environment - ordinary motor oil will do in a pinch.