I recently ran a clamp force test using the Maximus Clamp and thought I’d share the results here for anyone curious about how different tubing options hold up under real pressure.
This clamp is designed to work with standard steel tubing you can find around most shops, and I wanted to explore what kind of clamping force we can actually expect from three different materials:
- 1" x 2" solid bar stock
- 1" x 1" square tubing (2 pieces)
- 1" x 2" (0.120 wall) tubing
The Setup:
- Maximus clamp mounted 2" off the table
- Load cell placed to measure in a consistent spot
- Torque wrench set to 25 ft-lbs
- All tests started at the same torque, and then I manually cranked further to see how far each material would go
- We measured deflection with a tape and kept the setup consistent across tests
What I Found:
1. (2x) 1x1 Tubing:
- Hit ~2,450 lbs before the wrench clicked
- Significant bowing (over 1.5" deflection)
- Very flexible—felt like a spring
- Next step: added tack welds to stiffen it up and re-tested (more on that below)
2. 1x2 Tubing (0.120 wall):
- Easily hit 3,000 lbs with very little bend
- Deflection was around 1/4"
- Good balance of weight and strength—my personal favorite for general use
- Still had room to go past 3,000 lbs with hand torque
3. 1x2 Solid Bar Stock:
- Started climbing quickly—jumped past 2,800 lbs with ease
- Reached 4,000 lbs with almost no flex
- Deflection: only about 1/8"
- This stuff is a beast, but HEAVY. Not something I’d want to haul around unless max clamping force is absolutely necessary
Bonus: Welded 1x1 Tubing Test
I took the original 1x1 tubing and added a few tack welds to stiffen it. After letting it cool down, I re-ran the test.
- Hit nearly 2,900 lbs
- Big improvement over the non-welded version
- Deflection dropped significantly
- Proved how much stiffness can be added with just a few small welds
Takeaway:
This test really highlighted how important bar rigidity is when you’re talking about applied clamping force. It’s not just about the torque you apply—it’s about how well that force gets transferred without deflection.
Each of the materials have their benefits. Personally I like to use the 1x2 120-wall tubing because it hits a nice, balanced, sweet spot. But if you’re chasing maximum force with minimal deflection, that solid bar stock can’t be beat (as long as you’re okay with the weight).
Hope this was helpful or at least interesting to those of you who like to geek out over this kind of shop testing. If anyone else has run similar tests or has other tubing materials they’ve tried, I’d love to hear how they performed!
Thanks for reading—and as always, you can check out the Maximus Clamp lineup (and now our New Lumber Clamps too!) over at the Fireball Tool website.
Jason