I didn't talk about how the moving jaw stays in place when tightened. Should I cover this in another video?

This might be favourite opening line to a woodworking video 😂

I haven’t read all the comments, but it should be mentioned that adding hockey stick tape to the handles (grip tape) as Rob Cosman does will give more purchase... resulting in a better grip for more torque.

i love your non BS approach to videos. thanks, looking forward to watching more of your videos

Wait, is this Special Clamp Theory, or General Clamp Theory? And how does that tie in with the Gödel's clamp rack incompleteness theorem?

I thought it would be boring... you make it like a science project. I have NEVER lubricated my clamps and now I feel so STUPID! Going to get the lube...

One of those moments when something that makes perfect sense has eluded you for so long. Now I obviously need to lubricate my clamps. Thanks for sharing, Marius!

I just trudged out to the shop through a foot of snow to lubricate my clamps. Thanks for the shop tips.

Marius...it's the simple things that make a difference. I agree with your suggestions and have two more to add: Handle Diameter and Surface Finish. I find some screw handles have too small a diameter and have a very smooth finish that makes a good grip difficult. I have found that some foam pipe insulation of the right diameter slipped over the handle and glued in place helps make a huge difference. You did a fine job of summarizing the key points.

I'm surprised you didn't talk about the sliding jaw and how it grips the bar. Initially you'd think it would just slide away down the bar but instead as the clamping pressure increases, it bites onto the bar and won't move. I think this is because the 90 degree angle to the bar opens up a little. Instead of sliding on the whole inner surface of the hole thru the jaw, it now only contacts the bar at the ends of the hole where the outer edge of the hole digs into the bar.

Really love your videos!

Omg this video is amazing! Absolutley love your description and how you explain everything. Love it! 😍😍😍😍

Thanks for teaching an old dog something new! Also thanks for the new video!

A surprising and valuable explanation - thank you.

You should also think about mechanical advantage when turning the clamp handle. It's not a problem with modern clamps with hexagonal rubber handles, but round wooden handles are crazy hard to tighten. Bob Cosman has a highly effective trick to overcome this using hockey stick tape to wind a spiral around the handle. It works like you wouldn't believe. The lube idea is a good reminder though as it is something I bet most people don't think of. We lube our planes with candles, and make large screw easier to put in with paste wax, so this is not a huge stretch.

Great video; a topic that is quite unique. One should know each tool in the workshop thoroughly.

That's a great tutorial thanks for the science behind something so simple there's always an underlying factor to everything isn't their

Probably the best way to think of how a screw works, is think of an inclined plane wrapped around a shaft, which is exactly what a screw is. Think pushing a wheelbarrow up a ramp: The steeper the ramp, the more effort it takes to move the load. Likewise, steeper-pitched screws require more torque to turn. Fatter handles are a logical workaround, as they offer more leverage (as shown in the vid).

Thanks Marius...very good information and explained very well.

Well explained! I support the comment about trying to measure the force increase due to effective lubrication of the threads. Maybe a strain gauge, spot welded to a piece of metal of lower elastic modulus (to magnify the effect) would measure the delta force well. As an afterthought, it may be more suited to a woodworker to measure the penetration depth of a suitably sized ball bearing placed between the clamp face and a piece of softwood. Tightening as much as you can each time (unlubricated vs lubricated) will reveal a depth of impression which is proportional to the applied force. 😀