Bench hook question

[Mike Allen1010]

What diameter should holes be in bench top for 7/8" diameter steel bench hook?

I have bench hold downs from Japan woodworker that are 7/8" diameter solid steel poles with cast "hooks". My old bench had 2 1/2" thick particle board central surface . I had some problems getting the hooks to hold, even after roughing the surface of the poles.

I just finished new bench w/ 3" thick maple top (I'll try and post some build pics later this week), does the thickness and hardness of bench top wood effect how well bench hold downs work? Wouldn't mean I need holes larger than 7/8" diameter of poles? Is 3" thick bench top too thin for geometry of these hold downs to work?

Isn't the concept that the hole is slightly larger than diameter of pole and therefore "racks" when struck with a mallet and the friction created by racking holds work in place?

I would love some of the LV hold down that fit my 3/4" dog holes but $80 a throw is too rich for my blood.

After investing lots of time and especially sweat building my Ruobo with hand tools, I'm reluctant to drill big holes in the top unless I know their going to work.

Many thanks for for any advice and suggestions.

Mike

[Garrett Ellis]

You may be better of with some Gramercy holdfasts:

http://www.toolsforworkingwood.com//Merchant/merchant.mvc?Screen=PROD&Store_Code=toolshop&Product_Code=MS-HOLDFAST.XX&Category_Code=TL

3/4" seems to be more of the standard size for bench accessories.

[Greg Wease]

Why don't you ask Japan Woodworker for the correct hole size for their holdfasts since you already have them--otherwise, +1 re. Gramercy holdfasts and 3/4" holes. And 3" isn't too thin; could be too thick if the holdfast can't rack enough to tighten depending on hole clearance.

[Paul Incognito]

Why don't you drill some different sized holes in a 2x4 and see what works best?
Paul

[Brandon Craig]

I would make a sample sized piece of maple that is the same thickness as your bench (3") and then make a couple of test holes. My guess is that 1" will work best for those holdfasts, but it's difficult to know for sure. I've heard that the fastening of holdfasts described as a mystery -- you won't really know until you do some tests!