Sheet metal score bending - Angle grinder guide

**ruxu** · Nov 28, 2017, 08:43 AM

As many of you know one way to bend thicker sheet metal without a brake is to score the backside of the sheet at the bending points. Freehand scoring with an angle grinder is not that easy if you try to get accurate bending lines. I am just making a swarf tray from 1,5 mm steel plate so I had to make a quick improvement to the process.

What I did was a U-shaped slider that I fixed to the free handle thread of the angle grinder.

Sheet metal score bending - Angle grinder guide-img_1731.jpg

This U-shaped slider runs on a 20 x 20 mm square tube that is clamped down on the sheet metal piece at a distance 38 mm + the intended sheet metal flange in my case.

Sheet metal score bending - Angle grinder guide-img_1732.jpg

As the angle grinder now slides on the pipe the only thing you have to do is to monitor the depth of the score that should be about half of the sheet thickness in this case.

Sheet metal score bending - Angle grinder guide-img_1730.jpg

When the workpiece is scored it is quite easy to bend the flange using suitable iron bars. Here is a trial 45 degree bend made on a 1,5 mm scrap piece.

Sheet metal score bending - Angle grinder guide-img_1735.jpg

**Frank S** · Nov 28, 2017, 09:37 AM

Nice setup, this process would work fine for any bends which will require no significant structural strength

**bruce.desertrat** · Nov 28, 2017, 05:05 PM

This will also serve well as a 'saw guide' for cutting stuff with my grinder! Great idea!

**Frank S** · Nov 28, 2017, 05:20 PM

Bruce I didn't think about using it as a saw guide probably since I never use a grinder to cut stuff

**bruce.desertrat** · Nov 28, 2017, 05:28 PM

I had to cut about ½" off of the width one leg of some angle iron a while back, maybe about 2' worth, and I don't have a bandsaw. I clamped a straightedge to run it along, which sort of worked, but also chewed up my straightedge and my edge didn't end up exactly straight

**skibo** · Nov 28, 2017, 07:40 PM

If you could get a really nice straight cut you could weld the backside or inside where you notched the cut and it would be absolutely strong enough for most needs! I had a 4' sheet metal brake, I didn't use it enough to warrant it and it was always in my way so I sold it. Nice work, not quite sure where the pipe is in your pictures, unless your talking about the square tubing?
skibo

**Frank S** · Nov 28, 2017, 07:43 PM

Originally Posted by bruce.desertrat

I had to cut about ½" off of the width one leg of some angle iron a while back, maybe about 2' worth, and I don't have a bandsaw. I clamped a straightedge to run it along, which sort of worked, but also chewed up my straightedge and my edge didn't end up exactly straight

Its jobs like those when I use my 14" chop saw instead of my plasma or torch still not ideal since heat from the abrasive disk can cause the product to warp. its times like that when I often think about converting to a low RPM cold saw with high volume coolant. I made a vertical attachment for 1 of my band saws which does a fair job just still hard to get a perfect cut. http://www.homemadetools.net/forum/v...8190#post38351

**DIYer** · Nov 29, 2017, 07:31 AM

Thanks ruxu! We've added your Angle Grinder Scoring Jig to our Metalworking category,
as well as to your builder page: ruxu's Homemade Tools. Your receipt:

Angle Grinder Scoring Jig by ruxu

tags: jig, angle grinder