Hammer A3-41 cutter block replacement screws

[Peter Mich]

I’d like to have a few replacement screws available when I rotate the carbide inserts on my Hammer A3-41 jointer/planer. Unfortunately, the Felder website indicates these screws are out of stock and won’t be available for 6 to 10 weeks.

Where else might I purchase the necessary M5 x 10 , TX20 screws?

510781

Peter

[Dan Friedrichs]

Hmm, sure they're TX20 and not 25?
https://www.mcmaster.com/94414A732/

[Peter Mich]

Dan,

Thanks for tracking down the screws at McMaster.

Boy, what a price difference: Felder 10 screws for $27.30; McMaster 100 screws for $11.34.

The screws in the cutter head are TX20. But, bumping up to TX25 works.

Peter

[Dan Friedrichs]

In a 100 pack, you could probably replace them all with the T25's :)

[Bill Dufour]

Stolen from Practical machinist:
Standard head angle is 60 degree.
They come in 43,50,54,60,62, 82 and a radius.
The standard ISO hole in most screw down inserts is a radius designed to handle head angle from 40 to 62 degrees and still seat correctly.
Very small inserts and some specials will be designed to use the 43-54 only as the top opening of the hole gets close to the IC of the insert.
Available in metric and english threads and all kinds of lengths to handle differing thickness inserts.
They all carry weird part numbers usually invented by the cutter supplier.
Sorting through these make insert numbers look simple.

[Bill Dufour]

Best tip is to clean the pockets well and use a torque wrench or torque driver to fasten them.
Bill D

https://www.amazon.com/Wera-05074710001-Kraftform-Screwdriver-Adjustment/dp/B003KN3GAA/ref=asc_df_B003KN3GAA/?tag=hyprod-20&linkCode=df0&hvadid=309813767497&hvpos=&hvnetw=g&hvrand=3936143642728360292&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032274&hvtargid=pla-420978971929&mcid=c94d6a7fe38e3d71a2e28705e0f68ba4&gclid=EAIaIQobChMI65P67q3PggMVVQKtBh1hqgqREAQYASAB EgJdUPD_BwE&th=1

[Peter Mich]

Bill,

Are you suggesting that there are variables in the dimensions of the screws other than simply M5 x 10 at play that I should be mindful of when searching for replacement screws? In other words, should I stick with the Felder screws to be certain they’ll mate properly with the inserts and holes in the cutterblock?

Peter

[Bill Dufour]

The head angle can be different. Just like common countersink angles for flat head screws and rivets. 82,90, 100, and 120 degrees are common ones.
Bill D

[Erik Loza]

…Are you suggesting that there are variables in the dimensions of the screws other than simply M5 x 10 at play that I should be mindful of when searching for replacement screws? In other words, should I stick with the Felder screws to be certain they’ll mate properly with the inserts and holes in the cutterblock?

Don’t quote me on this but I feel like there is some voodoo to the angles or dimensions of the Felder-spec screws. I vaguely recall a customer trying to source them out domestically and having the inserts not seat correctly, or something to that effect.

Erik

[Bill Dufour]

For standard inserts the forth letter of the insert designation is the screw hole size/type. I assume Hammer sells them with no insert designation.
Is the hole countersunk? If so too big a head will not go down below flush. use one of the existing screws to measure head max diameter and eyeball the angle.
Bill D

[Peter Mich]

Thanks for the valuable insights. I’ll proceed with caution and hope I don’t screw things up.

Peter

[Bill Dufour]

Look at the old screws angled flank. Is there just a thin ring of wear showing they only contacted in a thin line? If in doubt blue them up and see what happens when you install one and take it out.
BilL D

[Bill Dufour]

Here are a few choices to measure up.
Bill D.
https://www.rmctooling.com/torx-screws.php