Most of the generic Bridgeport size clamping sets I have seen use 1/2"UNC rolled thread studs and suitable tee nuts. Mine takes a 22mm A/F spanner (7/8&quot. I have a set with 12mm studs for the rotary table with the same hexagon size on the nuts. I always thought about altering all the hexagon sizes to 3/4" (19mm) A/F the same as the draw bar but never got round to it and just live with two spanners on the table. Enjoy the machine, they are a joy to use.

Except it's a good idea to use metric studs so you don't get confused by similar sizes in imperial and metric.

Hello Colin,

You may well find there is actually no choice in the matter and what is on offer will be metric anyway. I don't think it will matter one way or another.

Regards Brian

Get metric if not in the USA. The reason is that one day you will need some special clamping with extra long studs and only metric threaded bar and nuts will be easy to get to match your T-nuts.

When you know which size spanner fits the nuts best, which might not be the 'official' size then find one at a car boot sale to paint to match the mill / clamping set holder and keep it there.

I seem to remember reading somewhere that 16mm my be a bit tight, and as I was given a 85% complete set of 5/8" slot (1/2" studs) I have used that. I have considered changing to 12mm studs & making the t-nuts to suit but for the gain it is a lot of work when I have clamps that work. I have so far found it fairly easy to get extra studding, just have to ignore a few metric only suppliers.

If I was starting from scratch I would probably investigate the 16mm t-nuts, perhaps buying a single one to check it fits every where easily.

If I need smaller studs for some vices or items that 1/2" won't fit I will probably make odd t-nuts in metric though as I do agree that is easier to get hold of at your average DIY shed & probably cheaper now.

Baldric.