Cajuncharley

My Feedback: (2)

I'm somewhat confused on the metric thread of 5mm X .8 and US thread 10-32. This is the common size to bolt on props on most DA and 3W engines. I initially thought the engines were 10-32, but seems they are really set up as 5mm X .8. I would almost swear they are interchangable, but I am not sure. Can someone out there clear my fuzzy thinking about these two seemingly same sizes?
Thanks,
Cajuncharley

ScottK

My Feedback: (9)

From old post:


5mm is larger than 10-32. The use of 10-32 is warned against by another engine distributor.

(Snipped from another resource - FWIW)

M5 nut on 10-32 bolt: works, may strip the bolt if overtorqued a tad.

Short 10-32 screw in M5 hole: often works.

10-32 nut on M5 bolt: if it's a sleazy cheapo crapola quality nut,
it'll go right on Good 10-32 nuts will start, and then make you
wonder why it doesn't quite fit, and then if the bolt's a 5.x grade or
less, the bolt will often snap or strip.

M5 bolt in 10-32 threaded hole: Probably not a good move. May cause
vocabulary expansion.

To make matters worse, the typical M5 nut uses an 8mm wrench, and
*some* 10-32 nuts use a 5/16" wrench, which is just .003" smaller;
these two are infuriatingly easy to get mixed up.

In performing repairs, the two sizes as matched assemblies more often
than not can be freely swapped, since the typical US-made part that
was sized for a 10-32 bolt will have been drilled larger than is
needed for even the slightly fatter M5. European and Japanese
machining always did seem to favor greater precision than that used in
American consumer-level goods.

Cajuncharley

My Feedback: (2)

Scott:
Many thanks!
Cajuncharley

DKjens

My Feedback: (50)

Cajuncharley,
In other, and not as colorful words, if you use 10/32 bolts to bolt the props on, where M5 should be used, the thread in the aluminum hubs will strip after a little time, guaranteed.
DKjens

SST

My Feedback: (2)

I'd open it up and tap to 1/4-28, install & locktite a long (stainless if possible) setscrew and use as a stud with nylock propnuts.

mdavies31

DA's and 3W's come with 5MM prop bolts, why not just use them?
The DA-50 uses the 5MM on the prop, the cylinder bolts, muffler bolts and the carb, only one hex wrench, 4MM, to check everything.

POPPAFITZ

My Feedback: (7)

What is the correct thread for holding the spinner on the DA's and the 3W's.

mdavies31

The DA-50 uses a 5MM for the spinner, I don't know about larger DA's or 3W.

tande

My Feedback: (48)

Close only counts in "Horseshoes & Dancing"---