Hold Fast Dimensions

[Justin Green]

I'd like to make some holdfasts for my bench. I'm looking to make the type that were used in the Roubo-type benches. I have a friend who has a welding gear and metal stock and an anvil. I supply the beer for afterwards, he lets me heat up some cold roll and beat it with a big hammer. Basically going to play around - he said he might even show me how to put a twist or two in the design.

If the holes in your bench are 3/4", what diameter would you use? 5/8"? I plan on making a few of varying lengths, but didn't know how much smaller they needed to be than the hole.

[Joe Meazle]

I made a pair a while back during a blacksmithing class at the National Ornimental Metal Musem In Memphis. I had a buddy give me the critical measurments from his Gramercy holdfast he got from Joel at Tools for Woodworking. I based the shape on one that one of the smiths had made to use on his anvil. I used 3/4 round stock and the seem to hold just fine in 3/4 (+ a hair) holes on my bench. I would think 5/8 would work too. I think if your top is super thick 5/8 might be a better way to go.

Joe

[Justin Green]

The top is about 3 and 3/8 inches. It started out life as warped leftover southern yellow pine flooring. The glue-up was 4" thick. By the time I flattened, untwisted, and cleaned it up, I had a garbage can full of shavings and a thinner bench!

Thanks for the info.

[Robert Rozaieski]

If you bore the holdfast hole with an auger bit and brace, the bit is slightly bigger than 3/4" so I'd make the holdfast from 3/4" stock. My Grammercy's are 3/4" and fit perfectly in a hole bored by a #12 bit.

[Justin Green]

Well, I started the holes with a 3/4 router and finished them with a paddle bit, so they're really close to 3/4". I bought some 3/4" oak dowel to do for some dogs until I order or make some metal ones. I haven't bought a brace and bit set yet... Although the amount of dust the router makes is really starting to annoy!

Do the holdfasts eventually destroy the hole? I made my top from southern yellow pine, and that's not the hardest wood.

[Robert Rozaieski]

They'll burnish it to a degree but it will only compress so much. Your SYP should be fine. You don't want them tight in the hole anyway. The slight cant and spring of the steel is what makes them hold when you wack em down.

[george wilson]

I'd suggest that you countersink a substantial bevel around the holdfast hole.In yellow pine,the holdfast sooner or later will lever out a big splinter. In maple,or beech,the problem is not as acute. The bevel will help make the edge of the hole stronger. Best solution would be to get a real big washer,and inlay it around the hole,and screw it down. An industrial fastner company would have big washers,or you could get a nice,thick one from MSC. They are sold for use around milling machines,and are machined,with a black finish.

[Justin Green]

George, I'll check out the washers... ultimately, this was a "bench to build a bench", using leftover pine flooring (T&G siding), and leftover cedar fence posts and rails. My skills are such that I didn't want to ruin nice lumber or spend a ton on the first bench. This thing IS sturdy, however, but who knows for how long with a cedar base! It's drawbored, which really worked well, but my tenons weren't cut so nicely.

However, hardware for this bench can be moved to the next bench, which I know is coming. not even complete with this one yet...