View Full Version : Metric aircraft countersunk machine screws
Charles Longley
February 3rd 18, 08:51 PM
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.
AS
February 3rd 18, 09:54 PM
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'
Tim Taylor
February 3rd 18, 10:43 PM
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.
Charles Longley
February 3rd 18, 11:36 PM
Well it’s not DIN 965. That’s pretty much what you find in a hardware store.
Dan Daly[_2_]
February 3rd 18, 11:52 PM
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...
AS
February 4th 18, 12:43 AM
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/products/din-7991-10-9-iso-10642-flat-head-countersunk-socket/
Uli
'AS'
Charles Longley
February 4th 18, 02:52 AM
No they’re philips screw.
AS
February 4th 18, 03:41 AM
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'
Charles Longley
February 4th 18, 04:21 AM
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.
AS
February 4th 18, 04:44 AM
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'
Charles Longley
February 4th 18, 04:56 AM
The empty package says 4 mm and a 4 mm screw from the hardware store screws in perfectly. Sooo I am guessing it’s a 4 mm screw....
AS
February 4th 18, 05:21 AM
On Saturday, February 3, 2018 at 11:56:41 PM UTC-5, Charles Longley wrote:
> The empty package says 4 mm and a 4 mm screw from the hardware store screws in perfectly. Sooo I am guessing it’s a 4 mm screw....
Well, in that case, let us know what standard that strange screw is when you find it.
Uli
'AS'
February 4th 18, 12:05 PM
On Saturday, February 3, 2018 at 11:51:27 AM UTC-9, 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.
'Aircraft Spruce and Specialty' has metric aircraft hardware
john firth
February 5th 18, 05:11 PM
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.
aircraft hardware stores parts is an oxymoron!
JMF
Charles Longley
February 6th 18, 03:01 AM
Yeah I didn’t punctuate that correctly. It should have read- “ They need to be aircraft screws. Hardware store screws have the wrong taper on them.
February 6th 18, 06:29 AM
On Monday, February 5, 2018 at 7:01:33 PM UTC-8, Charles Longley wrote:
> Yeah I didn’t punctuate that correctly. It should have read- “ They need to be aircraft screws. Hardware store screws have the wrong taper on them.
One example a part number of a countersunk metric screw is 22256BC040010L.
22256 is the type of screw,
BC is the metal type,
040 is the diameter,
010 is the length,
If you google the part, number lots of suppliers come up. If you need a few, contact a helicopter operator that maintains Eurocopter Astar AS350 helicopters. There are thousands in the US, if that is where you are. there may be one close to see what you are getting.
Rob
Wade G
February 6th 18, 04:43 PM
When I had my beloved L33, I tried to track these down with no success. I spent a lot of time hunting and ordering what seemed to be close. Nothing was close. Only source was through Blanik and they were priced somewhere near $20 each from Czech Republic. They were for an inspection panel cover so I decided to go with the wrong taper and negate my OCD.
Bob Kuykendall
February 6th 18, 05:48 PM
When I needed a batch of metric screws with 100-degree countersink, I just sharpened a bunch of hardware store 90-degree screws on my lathe. Took maybe a minute each.
Bob Kuykendall
February 6th 18, 05:49 PM
On Sunday, February 4, 2018 at 4:05:21 AM UTC-8, wrote:
> 'Aircraft Spruce and Specialty' has metric aircraft hardware
Link?
Soartech
February 7th 18, 03:50 PM
On Tuesday, February 6, 2018 at 12:49:20 PM UTC-5, Bob Kuykendall wrote:
> On Sunday, February 4, 2018 at 4:05:21 AM UTC-8, wrote:
>
> > 'Aircraft Spruce and Specialty' has metric aircraft hardware
>
> Link?
http://www.aircraftspruce.com/menus/ha/machinescrews.html
February 7th 18, 04:56 PM
On Wednesday, February 7, 2018 at 10:50:55 AM UTC-5, Soartech wrote:
> On Tuesday, February 6, 2018 at 12:49:20 PM UTC-5, Bob Kuykendall wrote:
> > On Sunday, February 4, 2018 at 4:05:21 AM UTC-8, wrote:
> >
> > > 'Aircraft Spruce and Specialty' has metric aircraft hardware
> >
> > Link?
>
> http://www.aircraftspruce.com/menus/ha/machinescrews.html
See any metric screws there? Looks like AN/MS part numbers to me.
UH
Richard Pfiffner[_2_]
February 7th 18, 07:07 PM
On Wednesday, February 7, 2018 at 8:56:24 AM UTC-8, wrote:
> On Wednesday, February 7, 2018 at 10:50:55 AM UTC-5, Soartech wrote:
> > On Tuesday, February 6, 2018 at 12:49:20 PM UTC-5, Bob Kuykendall wrote:
> > > On Sunday, February 4, 2018 at 4:05:21 AM UTC-8, wrote:
> > >
> > > > 'Aircraft Spruce and Specialty' has metric aircraft hardware
> > >
> > > Link?
> >
> > http://www.aircraftspruce.com/menus/ha/machinescrews.html
>
> See any metric screws there? Looks like AN/MS part numbers to me.
> UH
McMaster Carr
https://www.mcmaster.com/#machine-screws/=1bgwklj
Stainless 100 degree countersink
Richard
www.craggyaero.com
Richard Pfiffner[_2_]
February 7th 18, 07:09 PM
On Wednesday, February 7, 2018 at 11:07:45 AM UTC-8, Richard Pfiffner wrote:
> On Wednesday, February 7, 2018 at 8:56:24 AM UTC-8, wrote:
> > On Wednesday, February 7, 2018 at 10:50:55 AM UTC-5, Soartech wrote:
> > > On Tuesday, February 6, 2018 at 12:49:20 PM UTC-5, Bob Kuykendall wrote:
> > > > On Sunday, February 4, 2018 at 4:05:21 AM UTC-8, wrote:
> > > >
> > > > > 'Aircraft Spruce and Specialty' has metric aircraft hardware
> > > >
> > > > Link?
> > >
> > > http://www.aircraftspruce.com/menus/ha/machinescrews.html
> >
> > See any metric screws there? Looks like AN/MS part numbers to me.
> > UH
>
> McMaster Carr
>
> https://www.mcmaster.com/#machine-screws/=1bgwklj
>
> Stainless 100 degree countersink
>
> Richard
> www.craggyaero.com
https://www.mcmaster.com/#machine-screws/=1bgwlmh
Steel 100 deg countersink
Richard
www.craggyaero.com
Bob Kuykendall
February 7th 18, 07:14 PM
On Wednesday, February 7, 2018 at 7:50:55 AM UTC-8, Soartech wrote:
> http://www.aircraftspruce.com/menus/ha/machinescrews.html
Yup, those are machine screws. Didn't see any metric ones, though I didn't check them all.
--Bob K.
Richard Pfiffner[_2_]
February 7th 18, 08:02 PM
On Wednesday, February 7, 2018 at 11:14:40 AM UTC-8, Bob Kuykendall wrote:
> On Wednesday, February 7, 2018 at 7:50:55 AM UTC-8, Soartech wrote:
>
> > http://www.aircraftspruce.com/menus/ha/machinescrews.html
>
> Yup, those are machine screws. Didn't see any metric ones, though I didn't check them all.
>
> --Bob K.
Mil Spec screw on McMaster Carr are metric and have the 100 deg countersink.
Richard
www.craggyaero.com
February 8th 18, 01:44 AM
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.
-----
I went through this a couple months ago. As noted above, metric countersunk screws have a 90 deg countersink, and of course there are different kinds of heads like flat or oval. I wasn't able to find a single supplier that had everything I needed, so ended up ordering some from Mr Metric (aka Mountz) and others from Bel-Metric. Needless to say I bought a few extra of each size!
Good luck,
Brian
Richard Pfiffner[_2_]
February 8th 18, 06:19 PM
On Wednesday, February 7, 2018 at 5:44:51 PM UTC-8, wrote:
> 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.
> -----
>
> I went through this a couple months ago. As noted above, metric countersunk screws have a 90 deg countersink, and of course there are different kinds of heads like flat or oval. I wasn't able to find a single supplier that had everything I needed, so ended up ordering some from Mr Metric (aka Mountz) and others from Bel-Metric. Needless to say I bought a few extra of each size!
>
> Good luck,
> Brian
Brian
Mil Spec screw on McMaster Carr are metric and have the 100 deg countersink..
Richard
www.craggyaero.com
Charles Longley
February 9th 18, 01:07 AM
I looked at the McMaster screws and they’re the wrong head size for Blanik’s.
AS
February 9th 18, 01:22 AM
On Wednesday, February 7, 2018 at 3:02:41 PM UTC-5, Richard Pfiffner wrote:
> On Wednesday, February 7, 2018 at 11:14:40 AM UTC-8, Bob Kuykendall wrote:
> > On Wednesday, February 7, 2018 at 7:50:55 AM UTC-8, Soartech wrote:
> >
> > > http://www.aircraftspruce.com/menus/ha/machinescrews.html
> >
> > Yup, those are machine screws. Didn't see any metric ones, though I didn't check them all.
> >
> > --Bob K.
>
> Mil Spec screw on McMaster Carr are metric and have the 100 deg countersink.
>
> Richard
> www.craggyaero.com
Richard - can you post a McMaster Carr p/n for a 'metric MIL-spec' countersunk Philips head screw? I can only find imperial sized ones under MIL-spec. Maybe I am not looking in the right place.
Thanks
Uli
'AS'
2G
February 9th 18, 05:35 AM
On Saturday, February 3, 2018 at 8:21:17 PM UTC-8, 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.
That head diameter is totally unrealistic; it should be about twice the shaft diameter. Grind the head down if you want it less, but you will have a very small shoulder as a result.
Tom
Richard Pfiffner[_2_]
February 9th 18, 03:37 PM
On Thursday, February 8, 2018 at 10:19:25 AM UTC-8, Richard Pfiffner wrote:
> On Wednesday, February 7, 2018 at 5:44:51 PM UTC-8, wrote:
> > 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.
> > -----
> >
> > I went through this a couple months ago. As noted above, metric countersunk screws have a 90 deg countersink, and of course there are different kinds of heads like flat or oval. I wasn't able to find a single supplier that had everything I needed, so ended up ordering some from Mr Metric (aka Mountz) and others from Bel-Metric. Needless to say I bought a few extra of each size!
> >
> > Good luck,
> > Brian
>
>
> Brian
> Mil Spec screw on McMaster Carr are metric and have the 100 deg countersink.
>
> Richard
> www.craggyaero.com
woops the 100 deg was on the English cap screws.
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