Center Bits...

[Kelly Jons]

I'd like to get me some center bits. Any chance someone is making new ones? If not, what are good places to find some decent usable ones?

Also, any good place to get a nice Spofford brace or two?

Thanks for the info, guys.

Kelly

[george wilson]

Flea market hunting is about the only way. Be warned that center bits may not drill straight holes. They can,and will wander sideways. They were used to start holes for spoon bits when deeper holes were needed.

I think that 18th.C. drills were the most ineffective tools I had to work with. I used these types old old bits for 16 years in Williamsburg.

The French used a type of straight sided center bit which are illustrated in Diderot. They were quite a lot like modern flat bits,but had a square shank. They would have drilled a straighter hole. I've never seen one in person,though.

[Joel Moskowitz]

Clico (clifton) still lists centre bits in their catalog. I don't know pricing or if they are readily available as a special order.

Otherwise call any decent tool dealer in England. I got my set from Ray Iles. Basically an almost brand new set of ibbotson's from around 1900. wasn't expensive either and should not be hard to get in sets.

Why you would want them is entirely a different story. Give me regular brace bits anyday. Center bits work fine but you have to apply a lot of force and they can wander.

[Bob Strawn]

A well tuned centerbit will cut an neat clean line at the outside of the hole. For a brace, they are a nice way to make a neat hole.

Some centerbits have a slight bit of spiral for ejecting waste, and a screw center to make it rather aggressive. I have a rather large one that I use for making bolt holes in posts. A ship auger is superior, for drilling out a hole in my opinion. However with the right centerbit and a brace, I can easily make a nice big hole that would be no fun at all to make with a power drill.

I rather like a centerbit, but only for straight holes with a brace. To me the real advantage of a centerbit is that they are easy enough to sharpen in the field. A spoon bit gives you more options on angle, but you have to be much more careful to sharpen a spoon bit correctly.

If you are an orphan pirate that plans to take up burglary, then you absolutely need a centerbit. Tarantara, tarantara.

Bob

[Chuck Nickerson]

I've recently started trying to make them. Tool steel is expensive enough that I can't imagine selling them at a profit. Adam Cherubini gave me some tips on proper geometry, so the bits are starting to get better. I'll need to PM Joel about 'any decent tool dealer in England'. His list must be different than mine; hen's teeth they are.

[george wilson]

I am beginning to wonder if we are talking about the same kinds of centerbits. I was referring to the 18th.C. variety,which look sort of like flat bits,except that their edges curve inwards from the cutting diameter down to the shank diameter. They have a triangular point,not a screw point at all.Since their edges curve inwards towards the shank,they are very prone to drift sideways in a hole.

Guess I was in a museum too long!!

[Joel Moskowitz]

I am beginning to wonder if we are talking about the same kinds of centerbits. I was referring to the 18th.C. variety,which look sort of like flat bits,except that their edges curve inwards from the cutting diameter down to the shank diameter. They have a triangular point,not a screw point at all.Since their edges curve inwards towards the shank,they are very prone to drift sideways in a hole.

Guess I was in a museum too long!!

Yip - those are them.

[harry strasil]

Centre Bits aren't hard to make, Spoon Bits are tho.

[Chuck Nickerson]

Harry - center bits aren't hard for you to make. I've spent a whopping three days at the anvil.

[Dewald van Lamp]

I picked up about 15 centrebits of different sizes at a local school when it closed down their woodworking shop.

I only now see that most of them have their triangular centre points broken off...



Oh, well, I'll find a use for the shafts..!

[george wilson]

That must have been a very old woodworking shop!

[harry strasil]

That's not a problem Dewald, just get some one with a mig welder, gas and wire no flux core stuff to build them out a bit and grind to a point, the spike doesn't need to be hard.

[harry strasil]

Chuck you want me to work up a little demo on how I make Centre Bits?

[Bob Strawn]

I am beginning to wonder if we are talking about the same kinds of centerbits. I was referring to the 18th.C. variety,which look sort of like flat bits,except that their edges curve inwards from the cutting diameter down to the shank diameter. They have a triangular point,not a screw point at all.Since their edges curve inwards towards the shank,they are very prone to drift sideways in a hole.

Guess I was in a museum too long!!

My learning is from books, posts and articles mostly, as a result I am rather prone to all manner of error. but I will happily defer to you, George. I have been bold enough to disagree with my betters on occasion, but only when I have serious multiple source backup and physical evidence. I can however pull up enough sources to perhaps explain my ignorance. I can even give available references to the spurious sources of my folly.

Just a couple of years ago, while I was acquiring my first brace bits, I was led astray while reading Appleton's dictionary of machines, .... from 1856 (Page 168) I saw a similar bit to one that I had obtained, probably from Brass City Records and Tools, that Appleton called an american screw auger or a centerbit for deep holes. So from that point my perception of what was called a centerbit became sadly warped and my path on the road to ruin was assured.

With such horrid enablers such as answers.com around showing a screw center with deep wings on either side while calling it a center-bit, how could I even know the folly of my ways?

I did have a chance offered at one time, by The teacher's hand-book of slöjd from 1891 where they called a bit with a screw tip an auger bit. But between the reasonably modern reference, the older reference and the screw center on my lathe, I foolishly jumped to the conclusion that a centerbit might have some spiral on the stem and spiral on the center and still be considered a centerbit.

Bob

[harry strasil]

OT a bit, but a little History.

The Modern Auger Bit as we know it, with the screw end and the twisted flutes was invented by a Blacksmith (Name lost to time) who had a habit, strong drink from the Apothecary next door owned by one Russel Jennings. To pay his bar tab so to speak the blacksmith offered the Patent for the Auger bit to the Druggist, who started a factory and went into production, the rest is History. FWIW