M3 Fasteners
McMaster-Carr has plenty of M3 socket-head fasteners. Not crazy expensive. https://www.mcmaster.com/#standard-socket-head-screws/=1550rv9
McMaster-Carr has plenty of M3 socket-head fasteners. Not crazy expensive. https://www.mcmaster.com/#standard-socket-head-screws/=1550rv9
Smallparts.com - good assortment of just about any fastener.
pack of 100 304 SS socket cap screws 4-40x0.25 for $11
SC028C-006-C-SK-S4
pack of 100 in 0.375in length for $23
http://www.smallparts.com.au/store/item/sc028c010csks4/screwscapsocket303304stainless/
pack of 100 304 SS socket cap screws 4-40x0.25 for $11
SC028C-006-C-SK-S4
pack of 100 in 0.375in length for $23
http://www.smallparts.com.au/store/item/sc028c010csks4/screwscapsocket303304stainless/
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the Belleville washer is an excellent hold down. It compensates for different expansion ratios as temperatures vary.
Currently looking for an affordable source for 100pcs M3 size (including shipping costs). Found a great source in the UK, but shipping is more than the parts.
I might as well get a couple hundred of these, because it seems that M3 is a pretty common size for fastening transistors...
Maybe other people would be interested in a group buy, or buying some from me if I order for everyone?
Stainless Steel (300 series)
M3 size
Belleville spring washer
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Charlie,
See post #22 above. The M3 socket heads are about 4 cents apiece, depending on length, in quantities of 100. The Belleville washers are 20 cents in steel and 50 cents in stainless. I use McMaster all the time; shipping is not unreasonable.
George
I use McMaster all the time, too. Maybe I am cheap, but $0.50 per tiny Belleville washer (even for stainless) is a little more than I want to pay. If I order in quantity I can get many, many more for the same (total) price, especially since McMaster shipping charges are not inconsequential.
I already ordered plain SS washers and SS socket head cap screws in the M3 size, plus a couple of taps and 2.5mm drill bits. It's just down to the Belleville washers at this point. Just for the little projects I am building now, I will need 40 pcs of each (BV washer, plain washer, cap screw). That would be $20 in BV washers alone!
AliExpress has M3 and free shipping.
100 pieces stainless M3 x 8mm $4.75
http://www.aliexpress.com/item/32573038131/32573038131.html
100 pieces stainless M3 x 8mm $4.75
http://www.aliexpress.com/item/32573038131/32573038131.html
I'm all set (e.g. have already purchased) M3 fasteners and washers. I'm just looking around for a more cost effective source for M3 Belleville spring washers.
I saw the same sort of pricing as well. If I order at least 800 of them they are 1 US cent each and shipping is still the same cost. OD is 7mm, so may need to buy "oversized" 9mm OD M3 plain washers for the BW to flex against. Same company has these parts as well. All are stainless steel.
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