Be aware that the two sides of the angle are unlikely to be dead square to each other, either. That might need to be taken into account when machining the top surfaces of those two legs. It might need assembling first and then machining.

Looks like poor quality rolling. Most good quality angle is “sharper” than that. You might try a different supplier, but really you need to look at the material before purchase in today’s world. Bit of JB weld if the area is at all visible might be easier.

It’s a bit of a poor one, maybe end of the roll?

But at the end of the day it won’t show once it is all filleted in with Bondo (body filler)

I doubt the steel mills in China and India take much notice of BS anything. There is some pretty poor steel on the market in recent years. Yes it should be rejected, but who checks it? Nobody. Once again it is left to the consumer. Who only finds out when he gets it on the job and has started cutting it up, or starts hitting “diamonds” that even carbide tooling will not cut. (Rumour has it that Chinese recycled steel contains discarded carbide inserts that somehow make it through the smelting process. Seems unlikely, but some of those hard spots in their bright bar seem that hard, or harder. They will tear the tips off carbide tooling and snap HSS clean in half.)

having welded two bit sof angle into C channel a couple of times you do have to watch for it closing up. I’d be inclined to use 10mm flat material and use 3 pieces to make the U shape. Sides full height and middle cut to fit between. Some counterbored holes in from the side will hold it together and can be filled with JBW or body filler at the end when the other cosmetic work is done.

This sort of thing wich is the sole plate of an engine

Ive just squared up a piece of hot rolled angle 75 x 90 on the shaper and it only needed 0.4mm shaved off each face to leave a razor sharp corner so if I were you it would go back.

Not long before I retired i was involved in making a mould tool for Jaguar. One half weighed about 500Kg and we had spent two weeks CNC machining when we found a hard spot which would not cut as when tested with a hardness tester it was about 60 RC hardness. The customer would not accept the piece of material and it had to be replaced and the metal supplier would only replace the steel, P20 sulpher free and no compensation for time and tooling loss. It was found the material was from China and had a delay in replacing from alternate source.

David

Where are you ? I have assorted off cuts of alsorts and may be able to help. Another thought is to use a lump of C section and cut out the middle. How long do you need ? Noel.

On 10 October 2024 at 19:24 Nicholas Farr Said:

Hi, well I’ve cut, drilled, bolted, welded, etc.  very many tons of hot rolled angle iron, both equal and unequal, and of many different sizes.

…

As far as I’m aware, hot rolled sections have always been considered as structural, and not directly associated with precision work, but can be used if you are prepared to do a certain amount of machining on it, …

Regards Nick.

I’m with Nick!  Do Model Engineers understand that the common mild-steel we use is sold for structural work, and isn’t particularly machinable?   Hot rolled may be covered in scale, and isn’t dimensionally accurate.  For rough work, hidden behind a facade. Bright mild-steel is also structural, but is finished to a higher standard, for front-of-house.   However, that bright mild-steel isn’t particularly machinable is revealed by it;s tendency to warp.

Something odd going on with reports of poor steel quality and I note they mostly originate from small workshops or the internet, not large-scale steel consumers like car-makers or shipbuilders.

Maybe this is because small workshops are more likely to use the wrong steel, are more likely to set work up incorrectly, and cut at the wrong rate with a blunt or inappropriate tool.  Or fail to apply cutting fluids, clear swarf, or use best technique.  Amateurs doing their best with what they have struggling more than pros with the right tools, well-chosen materials, and expertise,

Consider hopper’s rumour that Chinese steel contains carbide inserts.   In 2022 China made a billion tons of steel; at the rate of 1 insert per ton, that’s a lot of inserts!   The original version of hoppers rumour involved ball-bearings, presumably from the idea that steel-workers melt old bicycles in a pot, rather than bulk-loading a modern steel-works of advanced design several hundred tons at a time.  If either were true, there would be severe problems with steel sheet and steel plate.   If steel contained hard inclusions, rolling it into sheet would cause obvious defects, and that isn’t widely reported.  So  I put it too hopper that his rumour has a quality problem, it’s full of b*ll*cks!

Not impossible that steel contains hard inclusions.  A more likely source is bits of furnace lining.  This is a hard refractory material of very high melting point, that’s prone to flake off as the furnace ages.     Not much else that survives the extreme heat in a steel works, or the attentions of the works chemist.  The notion that adding recycled steel reduces ‘quality’ is also a myth.  Scrap contains far fewer impurities than raw minerals!

I’m much more impressed by official investigations than rumour.   Rumour damns the quality of chinese steel to hell and back.  Properly researched investigations suggest most  steel is mostly OK.  Be amazing if it were all perfect.

Dave