Sharpening Centre Bits

[Andy Kev.]

Good Afternoon All,

I've just picked up a set of old centre bits and as you can imagine they will need a bit of work doing on them before being put to use. Do you think that this set of files will do the trick for sharpening them up:

https://www.dictum.com/en/sharpening/sh ... 97_1_12_12

Or do you know of anything better?

Thanks in advance,

Andy.

 

[ED65]

Those will work all right but they're overkill for centre bits!

Do you have any needle files or warding files already? They'll do the job perfectly well.

 

[AndyT]

Like Ed said - centre bits are not super-hard and should be easy to file sharp.

However, if you don't have anything suitable, a good buy could be a set of small diamond files. I bought a set of four, branded Trend, but doubtless available with other names or none. Flat, half round, round and triangular, I think. They are also good for sharpening profiled irons in moulding planes.

The budget option is wet and dry stuck to a suitably shaped stick.

 

[bugbear]

If the bits are badly worn/damaged/blunted you may want an ordinary file for rapid metal removal.

BugBear

 

[Cheshirechappie]

Andy, I'm sure you'll have found this, but Shannon Rodgers does an excellent video on centre bits, including sharpening them;

http://www.renaissancewoodworker.com/center-bits/

The proper auger file is nice to have, but it doesn't do anything a couple of needle files won't do. For the really small centre bits, you do need a really small file - a square needle file is ideal. I found it's actually quite quick to sharpen centre bits, and as long as you take care to keep to the inside of the scribing spur, maintain a clearance on the cutting lip and keep the centre spur central, it's just applied common sense.

Must admit I quite enjoy using centre bits, too. Rate of feed isn't dependent on the worm pitch as with an auger bit, but on how hard you're prepared to lean on the brace. They give nice, clean holes, too.

 

[Sheffield Tony]

The proper auger file is nice to have, but it doesn't do anything a couple of needle files won't do.

Sort of. It's more what needle files may do that an auger file won't, as it has safe edges. You may find proper auger files at Dieter Schmidt, if you are lucky.

 

[Cheshirechappie]

The proper auger file is nice to have, but it doesn't do anything a couple of needle files won't do.

Sort of. It's more what needle files may do that an auger file won't, as it has safe edges. You may find proper auger files at Dieter Schmidt, if you are lucky.

Strictly speaking, that's quite right, of course. However, in this instance, a modicum of care will prevent any terminal damage to the bits from the non-safe edges. I know it's not perfect, but like a lot of things in life, standard needle files will be 'good enough' to give satisfactory results here, I think.

 

[bugbear]

The proper auger file is nice to have, but it doesn't do anything a couple of needle files won't do.

Sort of. It's more what needle files may do that an auger file won't, as it has safe edges. You may find proper auger files at Dieter Schmidt, if you are lucky.

Strictly speaking, that's quite right, of course. However, in this instance, a modicum of care will prevent any terminal damage to the bits from the non-safe edges. I know it's not perfect, but like a lot of things in life, standard needle files will be 'good enough' to give satisfactory results here, I think.

Ordinary files, especially cheap ones, can be given safe edges with a grinder!

BugBear

 

[Cheshirechappie]

Absolutely! However, in this instance, I personally don't think the specific application for said files is critical enough to warrant the effort! (Well - I wouldn't bother, anyway!)

 

[Andy Kev.]

Thanks for the replies. I'll now have a think. The one advantage of the files I linked to is that they look like they could come in useful for any small, fiddly surface which needs a touch up.

 

[AndyT]

The little diamond paddles are indeed very useful. But you need some needle files as well, in any well-equipped workshop.

 

[Andy Kev.]

OK, I'll throw a couple of needle files into the mix as well. There's never a sensible case for not having a couple more tools.

 

[ED65]

Ordinary files, especially cheap ones, can be given safe edges with a grinder!

This. And what's more a safer edge than many a safe-edge file has from the factory, which can have sharp, or worse, toothed arrises.