Metric aircraft countersunk machine screws

Does anyone have a source for metric aircraft countersunk machine screws? Similar to MS24693S28. They need to be aircraft hardware store screws have the wrong taper on them. This is for Blanik L-23 & L-33’s.

On Saturday, February 3, 2018 at 3:51:27 PM UTC-5, Charles Longley wrote:
Does anyone have a source for metric aircraft countersunk machine screws? Similar to MS24693S28. They need to be aircraft hardware store screws have the wrong taper on them. This is for Blanik L-23 & L-33’s.

US-standard countersunk screws have a taper angle of 82degr. or 100 degr. vs. a metric screw having a 90degr. taper angle.
Is there a DIN or ISO standard specified by LET? If so, McMaster Carr carries them but I am not sure how an aircraft standard plays into that.
Uli
'AS'

On Saturday, February 3, 2018 at 1:51:27 PM UTC-7, Charles Longley wrote:
Does anyone have a source for metric aircraft countersunk machine screws? Similar to MS24693S28. They need to be aircraft hardware store screws have the wrong taper on them. This is for Blanik L-23 & L-33’s.

Last time we ordered some it was from Fastenal.

Well it’s not DIN 965. That’s pretty much what you find in a hardware store.

On Saturday, February 3, 2018 at 6:36:55 PM UTC-5, Charles Longley wrote:
Well it’s not DIN 965. That’s pretty much what you find in a hardware store.

Find an L-13 that won't be brought back - buy it cheap - lots of good spares. Gear etc like the L-23...

On Saturday, February 3, 2018 at 6:36:55 PM UTC-5, Charles Longley wrote:
Well it’s not DIN 965. That’s pretty much what you find in a hardware store.

Could they be DIN 7991 or ISO 10642? These are hex-insert type and not Philips screws. Here is an online source for them in grade 10.9:
https://www.fullerfasteners.com/prod...ersunk-socket/
Uli
'AS'

No they’re philips screw.

On Saturday, February 3, 2018 at 9:52:31 PM UTC-5, Charles Longley wrote:
No they’re philips screw.

Sorry - I should have been more clear: could you substitute the Philips type with the hex-insert type as per DIN 7991 / ISO 10642?
Uli
'AS'

The head diameter on that screw is too big. I need a 4 mm screw with a head diameter around 6.5 mm. I am not sure what the countersink angle is. Looks closer to 100 though.

On Saturday, February 3, 2018 at 11:21:17 PM UTC-5, Charles Longley wrote:
The head diameter on that screw is too big. I need a 4 mm screw with a head diameter around 6.5 mm. I am not sure what the countersink angle is. Looks closer to 100 though.

If it is not 90degr., then it is not likely to be a metric screw! Just because the Blanik is from Europe doesn't mean that the hardware they used on that glider is metric. My Caproni was made in Italy and it uses all imperial sized hardware.
Uli
'AS'