M3.5 x 10 or 12mm Long Truss Head Machine Screws....source?

[nevetslab]

Having found #6-32 x 3/8" SS Blk Truss Head machine screws, Philips at McMaster-Carr and ordered some, I've been trying to find the M3.5mm x 10 or 12mm Long Truss Head screws, either in Philips, Torx, or Slotted to replace the 2mm Hex Drive version that Ampeg has been using on their power tube sockets for securing the Hold-Down Clamps or Base Clamps. Yeah...the ones that strip out with the greatest of ease. Thus far, all I can find are Pan Head screws in that M3.5 pattern. The Truss Head screw is used there because of the heat height...it doesn't interfere with the power tube seating into the Octal Socket. Pan Head screws do. Yeah, I know changing to a Flat Head screw would probably do it, but I'd rather not, since it's not seating into a tapered hole for proper fit.

McMaster-Carr doesn't carry them, MSC didn't, Grainger...forget it, Amazon-com assortments were all pan heads. I got thru six google pages and stopped looking. Any thoughts?

[g1]

Fastenal?

[SoulFetish]

Having found #6-32 x 3/8" SS Blk Truss Head machine screws, Philips at McMaster-Carr and ordered some, I've been trying to find the M3.5mm x 10 or 12mm Long Truss Head screws, either in Philips, Torx, or Slotted to replace the 2mm Hex Drive version that Ampeg has been using on their power tube sockets for securing the Hold-Down Clamps or Base Clamps. Yeah...the ones that strip out with the greatest of ease. Thus far, all I can find are Pan Head screws in that M3.5 pattern. The Truss Head screw is used there because of the heat height...it doesn't interfere with the power tube seating into the Octal Socket. Pan Head screws do. Yeah, I know changing to a Flat Head screw would probably do it, but I'd rather not, since it's not seating into a tapered hole for proper fit.

McMaster-Carr doesn't carry them, MSC didn't, Grainger...forget it, Amazon-com assortments were all pan heads. I got thru six google pages and stopped looking. Any thoughts?

are you sure they aren't standard M3 x 1?

[SoulFetish]

also, you can try boltdepot.com

[Bloomfield]

Spaenaur has a few choices in chapter B of the flip-through online catalogue. The DIN 85 pan head standard is only 2.1 mm high if that will do; I didn't see truss head listed unfortunately.

https://spaenaur.com/catalog/B38/ There are other options like Phillips head and stainless on later pages.

[MichaelNuzum]

I am looking for some of those screws too! Do you think these might work? https://www.mcmaster.com/90991A118

I know they aren't the black oxide finish, but they seem to hit the right dimensions otherwise. It calls it a "button" head, not a truss head, but the height is nice and small. The screws I have from my amp are around 1.8mm head height. These say they are 1.65mm.

[MichaelNuzum]

Okay, so now I am really confused. I just contacted Ampeg and the phone support guy told me he had those screws listed as 6-32 x 3/8, not M3.5. I just pulled a 6-32 out of the bin and checked and it is not a fit.

Am I missing something? Did some models use the 6-32 and other models use the M3.5 screw?

[nevetslab]

Okay, so now I am really confused. I just contacted Ampeg and the phone support guy told me he had those screws listed as 6-32 x 3/8, not M3.5. I just pulled a 6-32 out of the bin and checked and it is not a fit.

Am I missing something? Did some models use the 6-32 and other models use the M3.5 screw?

Obviously Ampeg's support person is not familiar with the history of the SVT-CL/AV-VR amps' hardware. The earlier ones are in deed #6-32, but they changed to M3.5 thread. Not M3...those won't grip the thread pattern. I haven't tried the M3.5 with a button head yet. I was hoping to find a NON-hex drive pattern in Truss Head (which has the lowest head height). I'll take a look at that McMaster-Carr part you highlighted....thanks.

[glebert]

I see 10 and 12mm long M3.5 in phillips head on ebay with fast and free shipping. For some reason the 10mm ones seem to be either stainless or black oxide, the 12mm only stainless.

edit: my bad, those are pan head

[MichaelNuzum]

Obviously Ampeg's support person is not familiar with the history of the SVT-CL/AV-VR amps' hardware. The earlier ones are in deed #6-32, but they changed to M3.5 thread. Not M3...those won't grip the thread pattern. I haven't tried the M3.5 with a button head yet. I was hoping to find a NON-hex drive pattern in Truss Head (which has the lowest head height). I'll take a look at that McMaster-Carr part you highlighted....thanks.

Thanks for that clarification, nevetslab!

Ampeg's support person didn't seem like he wanted to be very supportive. Maybe he was having a bad day.

After telling me the incorrect screw size, he directed me to the list of authorized service centers for parts purchasing. Problem is, there are all of four listed for Colorado, one of the four doesn't exist anymore, the other didn't have the screws, the third doesn't sell parts to the public, and the fourth is a three hour drive on the other side of the state.

So, I just ordered the ones I linked to. Hopefully they'll work.

[Enzo]

The Ampeg support people are all new to it, they are at Yamaha. Imagine how good you'd be if tomorrow you had to start working a parts counter at an outboard motor shop. Or a medical supply company.