Sharpening HSS Parting Blades

Box cutter? How about a "real" utility knife and some coated blades?

I've been using box cutters to score thin sheets of Phosphor-Bronze so I can break off strips, but it is a tedious process, and as a result I'm looking for a better way.

Is it plausible to pick up so parting blades and sharpen them top a knifes edge on a grinder? I thought perhaps I could then make some sort of handle to hold them while I used them on the Phosphor-Bronze.

I know this would be an unconventional use for parting blades and any better ideas would be appreciated.

Thanks.

Darren Harris Staten Island,New York.

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Yeah, you can sharpen them to an edge. But it's kind of a waste. It sounds like what you want is something like a Murphy shop knife. I make them out of old power-hacksaw blades, which are generally made of HSS.

However, my experience with grinding the teeth off of a HSS power-hacksaw blade, and then shaping it, is that I eat up so much of the grinding wheel that I would have been better off buying one.

I just happen to have a box of unused Sandvik power-hacksaw blades and some old grinding wheels.

You can certainly sharpen to a knife edge, but I'm not getting how this would make a less tedious process??

What about tin shears?

A few other ideas...

Carpet knife (has replaceable blades):

Roofer's knife (has replaceable blades):

There are also several varieties of carbide scrapers. Maybe just the replacement blade could be used. Should be a lot tougher than what you have been using, but don't know if it would be sharp enough (shrug):

Leon Fisk Inscribed thus:

Whats wrong with a chop type paper guillotine ? I often cut 1mm sheet aluminum with mine !

Use a 4" angle grinder to rough out the blades and the bench/pedestal grinder only to finish the blade. Ot just finish them with a flap wheel.

-- John B.

Sure, why not? We used to use them to make "chisels" to bust screws in the skin of airplanes loose.

Don't think of them as "parting tools" just think of them as a chunk of steel and make anything you want.

-- John B.

Searcher was searching...

Searcher, there's a much easier way to score shim stock and thin sheet stock. It's fast and effective, because instead of just impressing a knive edge into the material, this method actually removes a thin line of stock.

Get thyself down to a good glass shop or plastics dealer, and buy a plastics scoring knife. I use one all the time to cut thin stuff, although the blades aren't usually hard enough to handle high-carbon steel.

However, once you use one and see how it's made, you'll be quick to make a "permanent" one yourself -- and a parting blade would be just the ticket.

Lloyd

SEE:

"skrawker"...

Your welcome.

That's a good tip, and, in fact, that's exactly what I did the last time, except that I already had a wheel on my 6" Milwaukee angle-head, which made fairly quick work of it.

I also used one of those blades to make a drawknife. Man, those teeth are tough to grind off.

How thick is the sheet? If you are cutting straight lines could you use a paper guillotine?

Scoring blades are the ticket for using a hand tool to cut sheet materials. Stanley markets them in long and short versions for their utility knives. I've used these scoring blades for decades to cut sheet brass, aluminum, plastics and thin mild steel. They also serve to make a clean break line for bending or folding most sheet materials.

Have a look around at the location of acrylic sheet materials (window replacement clear stuff) in the home improvement stores, and you might see a scoring tool which is just a thin steel tool with a hooked/notched cutter at the end.

These are used by pulling them across the sheet material, and it's helpful to start with a few light cuts before pressing hard for deeper cuts. I generally start at the end of the cut nearest to me, with a few passes, then continue by making several longer passes until I get to the full length of the cut.. this is especially useful in soft materials where the cutting tip may wander away from the guide/straightedge if attempting a deep cut at the full length of the cut on the first pass.

A HSS cutoff/parting blade would make a very good cutter, or even a carbide paint scraper blade. The tip just needs to be a thin V with the cutting face tilted away from the operator, so it cuts and lifts a curl of the material on the pull stroke. A tiny carbide scribe tip with a flat ground on it (like a D engraving/cutting tool) or a chipped carbide insert cutter could be brazed to a suitable handle (or possibly clamped).

I don't do it that way. I rough cut them to shape with a 4 ",1mm cutting wheel. A bit of touch up on the edges for shape and grind the tapered edge and hit 'em a lick with a flap wheel and Bobs your uncle.

-- John B.

I don't do it that way. I rough cut them to shape with a 4 ",1mm cutting wheel. A bit of touch up on the edges for shape and grind the tapered edge and hit 'em a lick with a flap wheel and Bobs your uncle.

-- John B.

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Aha. I'll have to try that. I have used those tiny silicon carbide wheels on a Dremel to cut off bits of hand hacksaw blades, but I've never tried a bigger one on the power blades.

Several of the guys in my high school machine shop class would anxiously await the changing of the power hacksaw blade, so they could get the discarded one to make a throwing knife.. by grinding away a lot of the blade on the honkin bigass pedestal grinder.

Mmmmm.. sparks

Several of the guys in my high school machine shop class would anxiously await the changing of the power hacksaw blade, so they could get the discarded one to make a throwing knife.. by grinding away a lot of the blade on the honkin bigass pedestal grinder.

Mmmmm.. sparks

Thanks everyone.

I'll have to give a couple of those ideas a try.

And speaking of hacksaw blades, I have to cut some down for use as backing springs for some leaf switches similar to the one shown here:

(I assume snips of some sort are the best tool for that job).

Darren Harris Staten Island, New York.

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A hacksaw blade will wreck your snips. It's too hard.

My favorite tool for cutting hand hacksaw blades is a silicon-carbide cutoff wheel in a Dremel. You will want to use some kind of abrasive cutter to avoid damage to good steel cutters, and a little cutoff wheel is easy and faster than most other methods.

If you're just cutting them off square, you can hold the blade in a vise and break it off, and then grind off the rough edge on a bench grinder.

I'll pick up some silicon carbide cutting wheels for one of my Dremel XPR 400 tools. The springs blades I have to make will be about 1/4" wide and 3" long.

Thanks a lot.

Darren Harris Staten Island, New York.