I've been struggling to drill out the remains of exhaust securing screws on my recently purchased Yamaha SRV250 (this was meant as a riding round bike but is full of problems!). HSS bits were making little impression so I thought for a tenner these might be worth while. And they were. Whizzed through the screws as if they were made of cheese. Very impressive.
https://www.toolstation.com/cobalt-drill-bit-set/p40442
Cobalt drill bits
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Rockburner
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Re: Cobalt drill bits
Will bookmark those - I need to drill out some snapped bolts on the Rocksters at some point.iansoady wrote: ↑Fri Apr 26, 2024 10:49 am I've been struggling to drill out the remains of exhaust securing screws on my recently purchased Yamaha SRV250 (this was meant as a riding round bike but is full of problems!). HSS bits were making little impression so I thought for a tenner these might be worth while. And they were. Whizzed through the screws as if they were made of cheese. Very impressive.
https://www.toolstation.com/cobalt-drill-bit-set/p40442
non quod, sed quomodo
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Skub
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Re: Cobalt drill bits
I miss borrowing such items from the factory store.
I have to rely on mates to borrow them for me now.
I have to rely on mates to borrow them for me now.
"Be kind to past versions of yourself that didn't know what you know now."
Walt Whitman
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Walt Whitman
https://soundcloud.com/skub1955
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mangocrazy
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Re: Cobalt drill bits
Cobalt drill bits are great, but they do need to be handled carefully as they are significantly more brittle than HSS bits.
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demographic
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Re: Cobalt drill bits
There's a decent set that Machine Mart sells, in halfmm increments from 1mm to 13mm.
Its just shy of 60 quid and I lost my last set and had to buy another recently.
Obviously I found the last set a few days later but I'm ok witb that, a few of the bigger sizes of the old set need sharpened but I'll get to it.
Its just shy of 60 quid and I lost my last set and had to buy another recently.
Obviously I found the last set a few days later but I'm ok witb that, a few of the bigger sizes of the old set need sharpened but I'll get to it.
Re: Cobalt drill bits
I was a bit(!) worried about that having read similar comments but these seemed to be fairly tough. I started with 4mm, not wanting to risk anything smaller, and even though it did catch a couple of times it didn't snap.mangocrazy wrote: ↑Fri Apr 26, 2024 7:38 pm Cobalt drill bits are great, but they do need to be handled carefully as they are significantly more brittle than HSS bits.
The machine mart set looks good, but £60? I'd just go for individual bits if and when I need anything over the 6mm that comes in the toolstation set.
Re: Cobalt drill bits
Almost essential for working with stainless steel. I have also bought some diamond tipped bits (not masonry type) which are great for hardened materials. I'm not sure about the longevity because obviously they can't be ground back to resharpen whereas the homogeneous cobalt type can. Buying this kind of stuff on Ebay can be hit and miss if it comes from China but sometimes you get lucky.