Well I would start by asking size of what? An engineer’s vise has a number of dimensions, these include:
- Vise Total Weight
- Vise Jaw Width
- Vise Throat Depth
- Vise Jaw Opening
- Vise handle Length
There are vise models with almost every combination and variation of the above dimensions. I will go through each dimension one by one and try to give some general rules about sizing.
Vise Total Weight
A quick search on amazon will reveal there are vises as small as 1.5lb (.68kg), and as large as 220lbs(99.7kg). You could make the argument that the 1.5lb vise is not an engineers vise, but these vise names are not standardized, so it may be a bit pedantic to do so.
The point is: there is a large variation in the size of vises. You can buy even larger vises than the 220 pounder above if you special order them.
Lighter vises tend to be built around portability, and are used for softer metals such as aluminum or brass. Larger vises tend to be bolted into the table, and will be used for harder metals like steel.
Vise Jaw Width
The jaw width is a measure of how wide the jaws are along the horizontal axis.
The vast majority of vises will have jaw widths between 3″-8″ (76.2mm – 203.2mm) . Again, you can always find examples that buck the general trend – like the 1.5lb vise mentioned above, it only has a jaw width of 1-7/16″ (36.5mm).
Vise Jaw Opening
The jaw opening is a measurement of how wide the mouth of the jaw can open. There can be quiet a range of jaw openings, but most vises will fit in between 2.5″ and 12″ (63.5mm-304.8mm).
Vise Throat Depth
The vise throat depth measurement measures how deep a vise is vertically from the top of the vise jaw down to the leadscrew/slide.
Throat depth can range from 2″ up to 8″ (50.8mm-203.2mm) with most vises falling somewhere in the middle like my yost 750-DI which has a 4″ throat depth.
What should you optimize for when choosing an engineer’s vise?
It’s easier to use a small work piece in a big vise than it is to use a big work piece in a small vise. Larger vises also tend to have more longevity, and can pay for themselves with less headaches/repairs/replacements.
But I know telling everyone to buy a 60lb vise is not practical.
Buying the right size vise is really pretty simple. Think of the largest piece of stock you will be clamping into your vise, and then get a vise that 1.5x bigger.
If you are still not sure, I have a guide to purchasing a vise that might help you.