Secondary bevels for dummies

[Marcel]

All,

I have been reading about sharpening here on the forum ( and come to the conclusion that it is part religion and part fact ).

My question:

Is there a rule of thumb or maybe even a list as to what Secondary bevel ( if any ) should be on the different type of chisels and and plane blades?

Thank you in advance

Mac

 

[woodbloke]

General rule of thumb is that the main ground bevel (the big one) is around 25deg. The honed bevel (made on a honing stone) is usually around 30deg and generally a little higher (maybe 32deg) if you're using A2 steel eg LN chisels - Rob

 

[newt]

General rule of thumb is that the main ground bevel (the big one) is around 25deg. The honed bevel (made on a honing stone) is usually around 30deg and generally a little higher (maybe 32deg) if you're using A2 steel eg LN chisels - Rob

+1

 

[Kalimna]

Thats quite interesting - making the secondary bevel a little higher for A2 steel. Why is that?

As a short follow on question - what about paring chisels in A2?

Cheers,
Adam

 

[woodbloke]

Thats quite interesting - making the secondary bevel a little higher for A2 steel. Why is that?

As a short follow on question - what about paring chisels in A2?

Cheers,
Adam

A2 steel will crumble if the edge is honed at 30deg...I know to my cost and so does the bottom of my LN block :evil: If a slightly higher angle is honed (say at 32 or 33deg...but I wouldn't go higher) then the edge is more robust without sacrificing the ability to hone a decent edge. The higher honed angle ought not to crumble in a moderately hard timber like oak, but if a lot of work is done in softer timber (say pine) then a lower honed angle (say 28deg ish) is benefical, but I would then recommend that the chisel is only used on soft wood...using it again on hardwood is sure to make the blade crumble or even snap at the edge, 'specially if some hard chopping is done. That's why 30deg (for O1 steel) is usually recommended as a general rule of thumb to suit most timbers - Rob

 

[Kalimna]

Rob - cheers for that, it seems like I have a night in front of the Jet grinder and a bunch of stones ahead of me

Take care,
Adam

 

[Marcel]

Thank you Rob,

Very interesting indeed...

With you referring to the "LN Block " I guess that, as to my question, secondary bevels also go for plane blades.?

You just opened a great opportunity for me justify to have two sets of chisels, one for hardwood and one for softwood :shock:

Your answer also leads to another question:

How can I identify the steel quality of the older chisels I have?? Half part of what I have is old A.E. Berg the other part is also old but unknown


Thank you in advance

Cheers

Mac

 

[mr grimsdale]

...
Is there a rule of thumb or maybe even a list as to what Secondary bevel ( if any ) should be on the different type of chisels and and plane blades?

...

I'd just stick to 30º for everything until you are confident about variations.
If you need to hone at 32º to avoid crumbly edges I'd do that and then put them on ebay as soon as possible (if you can't get your money back from the original supplier)!

 

[woodbloke]

With you referring to the "LN Block " I guess that, as to my question, secondary bevels also go for plane blades.?

How can I identify the steel quality of the older chisels I have?? Half part of what I have is old A.E. Berg the other part is also old but unknown


Thank you in advance

Cheers

Mac

The same sort of rules apply for plane blades...30deg is generally good for O1 blades and a tad higher for A2. It's difficult to identify the steel quality on older chisels, but it's generally thought that the quality of steel in older chisels was superior...I'm not sure about that personally as it depends which modern chisels you're comparing them to, some cheaper Chiwanese chisels are truly appalling whilst the Ashley Isles chisels that Matthew sells are excellent - Rob

 

[Marcel]

I have purchased some AI chisels from Matthew, and also some CI Falls just to see and feel the difference.

I'd like to try to get a full set of both over time

I also have the AI "Dovetail set" from Matthew

Cheers

Mac

 

[woodbloke]

I have purchased some AI chisels from Matthew, and also some CI Falls just to see and feel the difference.


Mac

The AI chisels are excellent in all respects and could form the basis for a good cabinetmakers set. The CI Fall chisels are much cheaper but the steel quality is still excellent and now that Matthew has re-handled them, they would form a very good general purpose 'starter' set. The side bevels are too high for fine work, but that's easily remedied if you have access to a belt sander and can grind a bit of steel away - Rob

 

[mtt.tr]

This helped me learn to sharpen my chisels and explains how to get a secondary bevel i used the guide and my chisels will slice paper and cut arm hair sharp i feel
http://www.antiquetools.com/sharp/index.html