So what’s really better in a vise, a small screw or a large one?
In a previous Fireball 510 vs. Record No. 6 test, the 510 put out huge force numbers. A bunch of people said it was only because the Fireball has a larger diameter screw basically, that it was cheating.
Time to find out if that’s true.
For this test, I built a small setup to measure how screw diameter affects output force. Every screw had 5 threads per inch; the only difference was the diameter. We applied the same torque each time (50 ft-lbs) and measured the output with a load cell.
Here’s what we got:
3" Screw → 2,220 lbs
2" Screw → 2,700 lbs
1 1/4" Screw → 3,200 lbs
1” Screw → 5,164 lbs
So, is the Fireball 510 stronger because it has a bigger screw? Nope. In fact, the Record No.6 and the Fireball Hardtail vise have the same screw diameter. A bigger screw diameter would also need a bigger handle; however, that also doesn’t mean it’s an advantage. If the thread pitch were the same, we could get away with a smaller diameter.
Screw diameter alone doesn’t make a vise better. It’s the design and efficiency that matter.
