Thread: Advise needed: Hand lever shears

we have one of those at school i cant say for aluminium but cutting 50x 3mm you get a rough edge and the material bends slightly.

Hello Lou

It will warp the alloy. I have a similar one to that in the H&F catalogue. I have cut alloy plate from 1mm to 3mm and it has bent or warped the cut, leaves a sharp edge on the cut too. Same as when I cut copper plate, galv sheet or metal. Mighty tool to have for cutting flat bar and rod though.

DD

Hello Lou

It will warp the alloy. I have a similar one to that in the H&F catalogue. I have cut alloy plate from 1mm to 3mm and it has bent or warped the cut, leaves a sharp edge on the cut too. Same as when I cut copper plate, galv sheet or metal. Mighty tool to have for cutting flat bar and rod though.

DD

I'm kind of assuming this is what you mean??

Hi All,
I bought mine yonks ago at a Sun. Market for $20.
I've just finished cutting some hardened Alum. Sheet.
What I found was, don't cut right to the end, but move it along as you cut.
Mine never Warped or what ever, but I did run it over the Wire Wheel.
I was filling in 1 of the Allum. Painting Platforms, Bunnies, Gorilla, $59.
This strengthens those Legs, so as to use to put the Small Wood Lathes on.
I left a bit of a hole so as when I want to climb up on to it, I have room to put my foot, so as to get on the Platform.
Pop Riveted with 6 P/Rivets.
Surprising how it makes it so much steadier.

The quality of the cut depends on the condition of the shear. If both blades are sharp and adjusted correctly it will cut that size alloy beautifully with no feather on the edge. Over the years I have recoed a couple of them where I worked. Got them both where they would easily cut paper. Luckily at both places I had access to a surface grinder to grind the blades. One of the shears was in pretty bad shape. Some d***head had used it to cut HSS hacksaw blades which had well and truly stuffed the edge of the shear blades. I had to take a fair bit off the blades to clean them up.
Once re sharpened you just put the shear back together, bring the top blade down to the fully closed position and then using feelers measure the gap between the faces of the fixed bladed and the moving blade. (over at least 3 points along the length of the fixed blade) Then you just shim out the fixed blade by that amount.

bollie7

Originally Posted by matthew_g

I'm kind of assuming this is what you mean??

Hello Matthew,

Yes that's what I'm talking about.

Hi all,
Thank you for your replies.

It seems its as I feared, I'm not going to get a good cut with the shears

At the moment I'm using a set of medium bolt cutters set up in my vise and they do a reasonable job.

However its its a lot of mucking about setting them up everytime that's why I was looking for a dedicated tool I could use as needed.

Has anyone got any suggestions of some other (resonably priced) cut off tool I could use?

I did think about an aluminium blade for my drop saw but I ruled that out as an over-kill and too noisy to use in my garage.

Any suggestions appreciated.

regards,
Lou

Lou
A good bench shear will cut your material without a feather edge provided its sharp and adjusted correctly. It might slightly distort the cut end of the piece you cut off. By that I mean the bit that is under the moving blade. This is because the blade starts cutting at the edge and moves across the work as the blade comes down.
What I forgot to mention in my first post was that if the sides of the fixed and moving blades of the bench shear are nice and flat without any deep gouges in them,they don't need to be surface ground. The blades can be sharpened using a bench grinder. Just grind the top edge of the fixed blade and the bottom edge of the moving blade. Don't let them get hot.
Reassemble and measure the gap, shim as required.
When using the shear use the adjustable stop to hold the work piece down. this will make the shear cut straight down rather than at an angle if the work lifts.

bollie7

I'd be surprised if the shear didn't perform better than the bolt cutters. All the bolt cutters I have seen deform both the top and bottom edges(or is this what you are after?)

If its possible on these shears, setting blade clearance to 5 to 10% of material thickness may improve things. It should at least mean the blades will stay sharp longer and reduced force needed. As the material will fracture rather then be shear (almost) all the way through. I'm not sure these machines are rigid enough for these niceties though

Stuart

Originally Posted by Stustoys

I'd be surprised if the shear didn't perform better than the bolt cutters. All the bolt cutters I have seen deform both the top and bottom edges(or is this what you are after?)

If its possible on these shears, setting blade clearance to 5 to 10% of material thickness may improve things. It should at least mean the blades will stay sharp longer and reduced force needed. As the material will fracture rather then be shear (almost) all the way through. I'm not sure these machines are rigid enough for these niceties though

Stuart

The bolt cutters I'm using do leave a uniform 'feathering' right along the cut edge but that's not a problem, my measurements can tolerate a 1mm or so difference in each lenght.

If I could get a shear to cut the same without bending or warping the cut edge it would be ok.
I dare say that some shears would be better that others and that's what I need to do; find the shears that give the best cut.

LOL, I did see an electro-hydrolic cut-off machine that would do the job perfectly (as well as many other functions) but at a price tag of $30,000+, its way out of my price range

I use one at work often, and they do need a bit of attention- sharpening and tightening so there is little play between the parts.
One thing I did which made a huge difference to the quality of cut was get rid of the floppy little hold-down. I bolted a very large piece of angle iron as a bed to the left hand side, level with the bottom jaw, using the existing bolt holes below. Then I welded a new hold down to the top frame, a screw down one with a decent swivel plate to clamp on the work piece. If I get time (working silly hours at present) I'll take a photo. Well worth the effort, and I often use it instead of a drop saw for flat bar.
Cheers,

Thanks for your input Andy Mac, look forward to see your photo.

How neat do you think it would cut 10mm X 3mm aluminium?

And how quick? (I need to cut 200 -300 lenghts at a time.)

regards,
Lou

The thing with all these shears is that they come unadjusted. Some posters have mentioned reconditioning shears, but my experience has been that these days even the new ones are so far out of adjustment that they would have a hard time cutting a sausage.

You have to firstly set the blades correctly - I did have a chart which gave the correct clearance for shearing different thicknesses (before my senile mother got hold of it). Basically set the blades so that they just slide past each other as bollie7 said - if that does not give satisfactory results you have to OPEN the gap a thou' or so, too far and you get a drawn out edge on the cut, too tight & you end up hanging from the handle with your feet in the air.

The other thing that needs adjustment is the hold down - often missing on 2nd hand machines. On cheaper machines it is just a bolt with a length of 10 x20mm bar with a single hole, but better machines have a slot in the bar and an oval slider (or a pin & bolt) so the bar can't rotate out of adjustment. This bit is important as it stops the metal being cut from rotating in the jaws, which effectively increases its thickness and also gives daggy cuts.