Brass rods, pipes, sheets and strips from S.P. Road, Bangalore

Copper content. With roughly 30 to 37 percent zinc the alloy stays a single alpha phase, which is soft and very ductile when cold. Push the zinc to around 40 percent and a second, harder beta phase appears. That beta phase is what lets 60/40 brass be hot forged and extruded easily, and it is also why it will not take deep cold drawing the way 70/30 does.

So the names in the trade simply describe the copper-to-zinc ratio. 70/30 is cartridge brass, 63/37 is the general-purpose yellow brass and 60/40 is Muntz metal. Add 2 to 3.5 percent lead to a brass near the 60/40 end and you get free-cutting brass, the material most turned components are made from.

Start from the process, not the alloy. If the part is deep drawn or spun, such as a shell, cap or cartridge case, ask for 70/30 cartridge brass. For blanking, bending and shallow pressings where cost matters, 63/37 brass does the job for a lower copper content. For hot forgings, extrusions, tube plates and heavy sections, 60/40 Muntz metal is the usual choice.

Turned parts like inserts, fittings and terminals almost always come from leaded free-cutting rod. If you are not sure which ratio your drawing really needs, our brass 70/30 vs 63/37 vs 60/40 guide sets the three side by side.

You will hear these three words on S.P. Road and they are worth understanding before you compare quotes. Extruded describes the process: a hot billet is pushed through a die to make rod or tube blanks. Electrolytic quality usually means brass melted from electrolytic-grade copper with tight impurity control. Commercial quality is generally made with a larger share of recycled brass and is fine for many non-critical jobs.

The difference shows up in iron and lead content, surface finish and how consistently the metal behaves in the press. Asking for the test certificate is the simple way to see what you are getting.

Sizes vary a lot across the trade, so we confirm availability at enquiry rather than list stock that changes week to week.

• Round, hex and square rods, extruded or commercial: see brass rods
• Drawn pipes, tubes and capillary in 70/30, 63/37 and 60/40
• Sugar mill quality tubes for juice heaters, evaporators and pans
• Sheets, plates, flats and strips, rolled or hot rolled, in SWG and metric thicknesses
• Spring quality strip in hard-rolled tempers

Give us the grade or standard (IS, ASTM, BS or EN), the form, the size and the quantity. For tubes, add OD and wall thickness or SWG. For strip, add width, thickness and temper. If you only have a part drawing, send that and tell us what the part does.

For press shops and machine shops in Peenya, Bommasandra and the older industrial pockets of the city, S.P. Road is close enough to send someone to see the material before it is cut. We reply on email or WhatsApp with what we can supply and the paperwork that goes with it, on a GST invoice. Buying from a brass supplier in Bangalore also keeps freight and transit time short for sugar mills and plants elsewhere in Karnataka.