An idea of the type of work you intend to undertake may help as someone building small aero engines will need different materials to someone making a 1/2 size traction engine or another restoring motorbikes. Also are your preferences metric or imperial.

As always depends on what you're doing. I only have 4 types of steel:

• For machining on a lathe or milling machine EN1A-Pb. (Or EN1A if Pb isn't available.) They are both free-cutting mild steels, easy to cut and get a good finish, but a little weak. They can't be welded.
• For general purpose, work EN3B in Bright and Black form. Machines reasonably well, but inclined to tear. Cheap, and can be welded. Bright is finished, which saves time but it can warp when machined due to inbuilt stress. Black is unfinished, and doesn't warp when cut. Bright is slightly stronger.
• Silver Steel and Gauge Plate are heat hardenable steels. In the US known as drill rod, which is a clue. They're used to make punches or anything else that needs to be harder than mild steel. Good for small objects that can be heated with a blowlamp.
• Piano wire is a hard steel used to make springs.

Silver steel is easy to use but expensive. If a large quantity is needed, cheaper hardenable steels are available but are trickier to harden. A big blowlamp or forge plus a certain amount of skill.

I only do general purpose work in Brass, Aluminium and steel where strength, toughness and hardness aren't a priority. If you're into safety critical work like motorbike axles, the steels I've listed are unsuitable. Ask again! Likewise, certain jobs need stainless steels, which are different again. . There are thousands of different steels available for specialised purposes, most of them not used much in home workshops though they might be.

What sort of work do you intend doing?

Rather than lay in a huge stock, my strategy is to buy what I need when it's needed in various sizes plus extra if it's remotely likely to be useful in future. It's not so much different types of steel that make stockholding expensive, its the variety of shapes and sizes needed – rod, plate, angle etc, all in Bright or Black form. Again depending on purpose, you may find certain sizes and shapes are far more used than others. The advantage of stocking metal close to the right size is it dramatically reduces the amount of cutting needed – and cutting is a waste of time and money. Not a good idea to turn a 6" block of steel down into a 4mm diameter bolt, or to spend hours sawing small lumps off a 12" girder.

Dave

I am not a model engineer, but the things I make and repair vary from the very small to the very large, and I grab any shape or size of any metal that comes my way. It gets catergorised into strip, bar, tube, angle channel etc for steel, and for all non ferrous, it is sorted by metal type. As new and better stuff is found, I send the less good quality stuff to the scrapman, or give it away to anyone who wants it. If you are going to build a project, just order the stuff you need, to the nearest round amount, and start your metal stores with offcuts and remainders. All you need to know is, is it machinable, is it hardenable, how hard can it be made, and could it be case hardened and be adequate? Most hard steels can be softened, worked and machined, and then rehardened, and old tools are an excellent source of hardenable carbon steel, especially files!

Strictly, Ian, the EN series is obsolete (introduced during WW2), but EN1A is the weakest of the mild steels. It is offered with and without lead, and the leaded version must not be welded or brazed, as it formed a weak joint. Both machine well, especially the leaded variety.

Bill

When I first set up my workshop, I purchased a lot of steel stock, some of which is not used after many years.

My advice is to make an inventory of what you intend to build, go thru the drawings and make a cutting list of the materials that you will need for the build and add a bit extra for each of the sizes that you require. That way you will have spare steel in the sizes that you actually use.

When you buy the steel, ask if they have an off-cut of the steel section you require but a bit longer.  It is often sold at a discounted price.

Paul

Edited By Paul Lousick on 11/09/2020 00:08:38

I buy my metal from a company called M machine, they have a big range of material and it’s all sold by grade, I like to know what I am buying. Plus they are very helpful.

I mostly buy my imperial stock at shows so that tends to be 12" lengths but if ordering tend to go for the suppliers that do 2ft lengths. I like to keep the following steel in stock and before a show will go through what I have and list what I'm getting short of. I also keep a piece of paper and write down anything that I'm getting low on as I use it up so check that too.

EN1A, 1/16, 3/32, 1/8, 5/32, 3/16, 7/32, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4, 1, 1.5 and 2

303 stainless 3/32, 1/8, 3/16, 1/4, 3/8

Silver steel 3/32, 1/8, 3/16, 1/4, 3/8

EN1Apb Hex 1/4, 5/16, 3/8

EN3 flats 1/8 x 1 & 2, 3/16 x 2, 1/4 x 1 & 2, 3/8 x 1 and 1/2 x 1

As mentioned above at the start of a new project a good way to get to know the drawings is to work through them listing what material is needed, also think about how you will hold and machine the part so enough length can be allowed for that.

For metric stock I tend to buy on line as not many of the ME suppliers stock metric materials, upto 12mm dia I tend to buy 3m lengths (posted as 3 x 1m) as it works out a lot cheaper than short 300mm length, upto 25mm by the meter and 500mm lengths above that. I keep a slightly larger range of metric than equivalents above as that seems to be what I'm using more of at the moment on stationary steam and IC engines.

This is a good example of why this forum is so good!

Btw it may be a good idea to introduce some sort of colour coding to the different types of steel that you intend to get, it can be difficult determining one type from another if they all get mixed up

As mine have……….. (unhappy face)

Regards to all

Derek

I have good stocks of mild steel "scrap" the majority of which is (fortunately) free-cutting. A small stock of this for general use would be useful – it is certainly the material to use when starting out turning/machining steel.

However, some times I either need to be sure of the material type or need a specific size – and this needs to be purchased as required.

So my advice would be if you can get it for free, then do so but just be mindful that you can only really guess what it is (unless the source offers certainty) but otherwise purchase as required.

Quite often you will need to buy more material than you need anyway (longer lengths etc) – so your scrap bin will grow anyway (just be sure to mark the off-cuts so you can remember what it is).

So, in general, I wouldn't buy stock on 'spec' – but if you can get some good freebies – then why not?

Regards,

IanT

+1 to that! Starting out I almost gave up because mischance led to my scrap box containing nothing but obnoxious metal! Decided my mini-lathe was rubbish because it couldn't cut metal, when given machinable metal it performed well!

Problem with scrap is many manufactured items are made of alloys specifically chosen for properties other than machinability. Cutting tools like lathes, saws, and milling machines work best with metals where the specification mentions good machinability or 'free cutting'. Manufacturing has a wide choice of metal bashing methods, and don't take home-workshop needs into consideration at all; threads are rolled not cut and grinding is much used instead of machining.

Similar issues with DIY store metal. Apart from being expensive Aluminium is too soft and steel gritty. Their Brass is on the inferior side of OK. Basically, DIY store metal isn't aimed at machinists. Don't be put off if it misbehaves.

My advice: at first avoid unknown metals like the plague. Before exploring scrap learn the ropes with free-cutting metals. Once you know what to expect from friendly metal you can tell instantly if an unknown material is causing trouble rather than the machine, blunt tool, or learner driver. Once materials are identified as 'difficult' they can often be used by changing technique, but wild guessing as a way of discovering how to proceed with them is painful. A little experience with decent metal first works wonders.

Dave

As a beginner always go for free cutting steel unless your project calles for something special. You have enough to learn with everything else so give yourself a break. If you are buying small amounts (unlike Andrew) buy as you need, you only hve to think a couple of days ahead. As an aside settle on a size for hold down fixings to T slots, angle plates etc and buy a few lengths of studding that size along with a bag of nuts and washers. When I started half my time was spent making studs and the like for setups.

regards Martin