Hi,

I want to make some racks for my bike, and want to use T45 tube (4130 is too complicated to weld).

Does anyone know where i can buy T45 tubing in glasgow area?

Thanks

Andy

Roll cage manufacturer?

http://www.keepingitmuddy.co.uk/ – they’re in Barrhead

Why is it too hard with 4130

thanks

pre-heat and post heat treat, plus more complicated to mix with mild steel.

plus I’ve built stuff (car chassis) with T45 before and it was easy to work with so better the devil you know and all that…

T45 or aircraft cromoly will be hard to find and cost a fortune.

General view in USA on mtbr framebuilders forum is that people don’t heat treat thin wall 4130 bike frames after welding – it is more an aerospace / heavy fabrication thing. There was a discussion on this in the last few months if you search a bit.

Ceeway have thin Columbus 25CroMo4 tubes in 1.5m lengths in various diameters down to 12.7mm diameter. It is about £10 + VAT a length and then £7 postage (regardless of quantity unless buying tons of stuff). It welds, brazes and bends OK and probably a better mix (welding) with mild steel than T45.

http://www.framebuilding.com/Spare%20Tubes.htm

Kinetics bike shop Ben is in Glasgow – maybe ask him nicely if he has anything to sell in the sizes you require?

I’ve only got stainless in 10mm and 7mm – oh, and I think some 531 about somewhere in 10mm-ish.

4130 doesn’t need heat treating, though, AFAIK.

Strictly speaking you should be careful welding T45 or 531.

The carbon plus carbon equivalent value should be below 0.54%.

The Manganese counts towards this at I think Mn/6.

So 513 or T45 with 1.7%Mn/6 = 0.29% carbon equivalent

Plus the Carbon which can be up to 0.25% = 0.54% total

That is why Curtis frames and all old 531 road bikes were brazed.

thanks all.