Which fastener on 1/2 by 3 1/8 in prefinished solid wood.. I have a Stanley-Bostitch M111 FS it's breaking off the tonges. What about A senco SLS 20 HF or a spotnails flooring stapler or other stapler ..? Advise would be appreciated... Doug

Yes, that staple size of the Bostitch (15 gauge) is probably too big for that 1/2" T&G. Consider trying a cleat nailer like the Powernail Model 50P.

HighPro Tools
AS-4090

Thanks Gary I am taking over this job after some other crew started it they used a cleat nailer that split the touges don't know what there air was set at or if gun was shimed to the right height it shot a small gauge cleat .. What about the High-Pro AS4090.......High-Pro it is.... Thanks Floorguy... 43 years in wood and carpet my first with Cypress...Thanks..Doug