holdfast specifications

[mr_skittle]

I was going to check into getting a couple holdfasts made by a local blacksmith group but they aren't familiar with what they are.  Can anyone provide "plans" or whatever a blacksmith might need to make one? I don't know the first thing about metalwork but I assume there is a standard format or instructions for this type of thing.

[Daniel S]

The episode of the Woodwright's Shop where Peter Ross forges them would give them a good idea of what you're looking for. If you tell them how long you want it to reach and how big of a hole you're using it in, they can figure out each side of the corner.

[overland]

It's pretty interesting: http://www.thirteen.org/programs/the-woo...hold-fast/

[PaulJohnstone]

I am not an expert on holdfasts by any measure, but from what I have heard from people, there are a lot of differences in quality between different types of commercial holdfasts.
If I was in your shoes, I would buy one which has good reviews, rather than having a blacksmith who has never made one try to learn how to do it.
Just seems like it is not worth the risk to get a homemade one.. No offense to your blacksmith, I am sure he is skilled, but it seems he has never made one if you are asking for plans.

[overland]

I say give it a try. Most holdfasts use 3/4 or slightly thinner steel bar, although the French holdfasts are thicker. The top can be curved, like a crook: it doesn't have to be 90 degrees, like the holdfasts Peter Ross makes. The crucial feature is the angle on the pad at the end of the hook. It needs to be less than 90 degrees to the shaft, in part because the steel has some spring to it, but also because when the hold fast is in the hole, it will be tilted back a little from straight up and down. The front of the pad should touch the work first. You can look around on the internet and see what other makers are doing. That will give you an idea of the shape.

[mr_skittle]

I do have some reservations about getting them made by someone who's not familiar but there is an excellent blacksmithing guild here in town and I'd like to give them a shot. Another reason is that I'll be using them while I conduct some hand tool classes and would love to recommend getting a holdfast locally. I'll watch the video asap and pass it on to the blacksmith and we'll go from there.

The top can be curved, like a crook: it doesn't have to be 90 degrees, like the holdfasts Peter Ross makes. The crucial feature is the angle on the pad at the end of the hook. It needs to be less than 90 degrees to the shaft, in part because the steel has some spring to it, but also because when the hold fast is in the hole, it will be tilted back a little from straight up and down. The front of the pad should touch the work first.

These are the kind of details that I imagine the blacksmith would find useful.

[tablesawtom]

I had a cast one that I gave to my friend, as a pattern, who happens to do blacksmithing as a hobby. I love what I got back. He said the steel in the old single tire irons was great of the job. I guess I would recommend holdfasts made from old tire irons. But not all black smiths are created equal. In my case he had something to copy which worked out well.

Tom

[mr_skittle]

Tire iron huh, Thats good to know. I saw a video where the guy was using an old prybar. It'll probably save me a couple bucks if I can recycle some steel.

[Phil S.]

I have a couple of the holdfasts from TFWW, but have always wanted a pair of Phil Koontz's holdfasts.  He passed his design along to Black Bear Forge so I may need to order a pair of them one of these days - http://www.blackbearforge.com/holdfast.htm

[Souperchicken]

As another data point, I took a beginner blacksmith class some years back, and with the spare time at the end I made a pair of copies of the Tools For Working Wood holdfasts and I still use them today.  

I used 3/4" round stock, so they don't work in 3/4" holes- you need some slop in the hole so I use mine in 7/8" holes.  I've consider hammering mine down to work in 3/4", but haven't.  So if you don't want the sharp square corner that Peter Ross can forge, just about anyone with a forge could make a pair- just start with less than 3/4" round stock if you want them to work in 3/4" holes.  Also I would say the sharper the corner, the easier it is to get it to release, since you have to hit the vertical part to get it to release, probably why they were traditionally made the way that Ross does.