Sharpening Carbide & Hardening metal hammers

[cardiffrob]

Sorry. 2 questions for the price of one.

What grinding wheel material (and colour) for grinding a carbide lathe tool tip.

Also, if you were making a specialised shape hammer head from Silver steel and had to harden/temper it through a specific colour would you heat it from the face of the hammer or heat it from the shaft end in order to get the right colour. Might seem like a dumb question but I've pondered it for a while and can see problems with both methods.

Yours stupidly,

Rob

 

[TechnicAl]

Sorry. 2 questions for the price of one.

What grinding wheel material (and colour) for grinding a carbide lathe tool tip.

Also, if you were making a specialised shape hammer head from Silver steel and had to harden/temper it through a specific colour would you heat it from the face of the hammer or heat it from the shaft end in order to get the right colour. Might seem like a dumb question but I've pondered it for a while and can see problems with both methods.

Yours stupidly,

Rob

Dont know about 1st question but if you are heat treating any steel it needs to be controlled in an oven so that the heat is at a set temp and even throughout the piece.

 

[mr_splatter]

Hi,

For grinding carbide you will need a green wheel. Can't really answer your hardening question.

 

[ben8vgte]

For the hammer, a old panel beater was telling me the other day. He has trouble with new hammers not being as hard as they used to be, so just goes over the face with a hardfacing rod on a stick set then grinds in down. I've not tried it as yet but I will with a old one to see.

Anyhow I think a hammer only wants the face to be hardend and the rest to be softer.

 

[Lawnmowerboy]

Remember Carbide dosen't need to be sharp like HSS does, You need a bit of a radius on the end to keep a good finish.

It's worth getting a diamond eze lap file to keep it good.

 

[Pete.]

Modern carbide can be very sharp according to grade and use. A green wheel will give a very rough finish to any carbide edge but it's about your only choice if you don't have a diamond or cbn wheel.

 

[Lawnmowerboy]

That's why I reccomended the diamond lapping stone to smooth off after a grind. The carbide isn't usually like a knife edge.

 

[cardiffrob]

I bought some cheapo tip tools from RDG but none of the wheels I've got here will touch them. Doh!
I'll have to measure the grinder spindle size and order up a green wheel, unless someone knows where I can get a new grinder with a green wheel already on it. Can never have too many grinders!

 

[Pete.]

You won't find a green wheel on a new grinder usually, you buy them separately. Even a cheapo diamond wheel is better than a green wheel usually though.

 

[outofthefire]

Dont know about 1st question but if you are heat treating any steel it needs to be controlled in an oven so that the heat is at a set temp and even throughout the piece.

Thats not true quite a few things cold chisels especially shouldn't be the same hardness all the way through, if the striking end was the same hardness as the cutting edge there would be a real danger of it shattering when struck.

A hammer wants to be hardened at about 270 to 280°c a purple to dark purple colour. If it was for light use you could just harden the face using the method below, but for much else i'd harden the whole thing which would need a decent heat treating oven to do properly.

If you just want to harden the face you could get heat it up to cherry red quench about an inch or so in oil, quickly clean the face with some emery paper so its shiny then watch the heat creep back towards the face once its the right colour drop the whole thing in your oil and leave it there. The same method can be used for chisels.

 

[TargaMk3]

Just find a good engineering company near you and get them to heat treat the hammer. Another solution is buy a good one which doesn't really help you but you know the old saying. "Buy in haste, again and again and again"

 

[cardiffrob]

Outofthefire. Great idea. I knew I must have been suffering from an attack of the stupids. Bleedin' obvious, now that you've pointed it out. Duh!

Just a one-off hammer shape to make some trumpet shapes for carburettor inlets. It needs to stay really finely polished to keep from marking the ali surface of the trumpets. Both the wooden and the poly-whatsit hammers get little marks on them.

Cheers!

 

[Pete.]

Why does it matter if there are tooling marks on the trumpets, or is it a purely aesthetic reason?

 

[cardiffrob]

I like to polish, polish, polish...

 

[TargaMk3]

Carburettor trumpets? I assume like the old Webber trumpets found on many a DCOE 40's or other variant's. They were spun on a lathe. See here ....http://www.youtube.com/watch?v=bXu_16eZKnw

or here ... http://www.youtube.com/watch?v=yRhOrew1oxQ

and they are called velocity stacks.

 

[cardiffrob]

I just did them with tube, sheet, hammers and a lump of oak from a staircase. Like this but longer and more polished...

http://imageshack.us/photo/my-images/51/b94531436c3a232ade2804e.jpg/

 

[TargaMk3]

That's some hammering there shows great skill I bow my head in admiration. Dis yo take a look at the vids I posted on you tube? Ian

 

[cardiffrob]

Heck. No skill here. Hit it until it looks the right shape, that's my moto.

I'd have preferred to spin the ali but looking at vids like those and another one where the 'spinner' has only 3 fingers convinced me that it would be an easy way to die. I lack the confidence to stick my hands so close to a running lathe, plus I only have a Hobbymat MD65.


Like most people on here I have seen the staggering skill (and I REEEEALLY mean that) of the likes of Chunkolini and Hotrodder and have felt inspired to have a go with the idea that if I can get it to be 1/10th as good as their work I'll be happy. After that it is just a case of practicing.

Sounds like I'm sucking up to the Boss but it is the honest truth. If the geniuses (Genii?) didn't post inspirational pics then we might not ever try. Keep it up, oh mighty metal Gurus!

 

[cardiffrob]

In case anyone wondered how I did it...

I cut a disc of 1050 (cheapo) 1.5mm ali sheet in a circle the size of a CD because it has nicely positioned holes to scribe round, annealed it, stuck it on a sand bag, pummelled it with a plastic mallet in a ring between the inner and outer edges, albeit staying back about an inch until the middle of the disc had risen. I then angled the middle of the disc sideways over the shaft of a hammer held in a vice and tapped the inner lip further over, annealiing again to keep it from splitting. 10 minutes max.

 

[outofthefire]

I've always fancied having a go at spinning, but every time i've asked on a forum for advice the reply has always been "don't if you like all your fingers" I might give it a go one day if I get a bigger workshop with room for an old woodwork lathe apparently spinning tends to begger up a metalwork lathe.