Old B&D Dewalt Radial Arm Saw Generic Parts

I have a 7770 Dewalt or B&D radial arm saw I purchased in the mid 70's
I dropped and "lost" the arbor nut and have been attempting to replace.

The arbor is 5/8 inch and it has 18 threads per inch and is left handed. On a simple look I thought it was a UNF but when I purchased a UNF 5/8 LHT nut for $1.50 it did not fit.

Any advice please - B&D do stock spares but the delivered price is more than $25.

PS I have the old instructions and parts lists and can provide pdf copies to anyone who requires

:)

You won't find a nut of any quality much cheaper than $25

Regardless of price what is the thread - I am curious

could you provide manual and parts list fot 7770

much appreciated

bob cleary
[email protected]

I have a 7740 and full manuals etc. My understanding is that these saws were built in Italy and badge engineered as DW/BD. If so, they might use a metric thread.

16mm coarse is 2.0 pitch, fine is 1.5mm, and extra fine is 1mm. 18TPI converts to 1.4111mm pitch, so I am guesing 16x1.5 ISO Fine may be the answer you are seeking, just ever so slightly coarser than 5/8-18. Can get thread guages onto my arbor for you tommorrow.

EDIT

I have just measured my arbor, 15.9mm dia over threads, 1.5mm thread guage too coarse by a small amount, 1.25mm (next finest guage in my set) too fine by a long way, so I guess that 18TPI (1.41mm pitch) would be about right. Sorry I can't be more help, I dont have a set of imperial guages or micrometer to test with. 5/8th converts to 15.88mm diameter so my measureed 15.9 is a close match, very slightly OS, but more significantly undersize for 16mm. Sorry I can't be more help.


EDIT AGAIN

Looked onlineat some of the UK parts places. This one shows the DW 125, DW1251, and ELU 1251 (all basicly similar motors etc to my 740/7740), as 16 x 1.5 LH, tried to check US sites for comparison in case there are metric and imperial versions. Most you could not correlate the parts in the parts list to the ID on the drawings, and the one I could correlate had the nut listed without any size details.