stoneman 10 #1 Posted August 10, 2010 How did they measure these. My teeth are 42" apart, but according to the interchangeability chart, my sickle bar, #7-1311, is a 50". It also doesn't show it interchanging with a commando 8, but it had been purchased with and used on a 67 857. : anybody ? Kiwi Kelly TT :D Share this post Link to post Share on other sites
rickv1957 70 #2 Posted August 10, 2010 Will have to check my manual ,Im thinking the 1311 is a short frame 40" and the 1312 is the long frame 50",Rick Share this post Link to post Share on other sites
Volfandt 7 #3 Posted August 11, 2010 I have the SMS-506 on my 876 and when I measure between the outer knives on each end I get 50". According to my manual which I'm not sure of the yrs it covers it indicates there were two sicklebar mowers offered. 1) 7-1321 (formally SMS-425) with a 42" knife bar. 2) SML-506 (formally SMS-506) with a 50" knife bar. Altho the 42" is what was spec'ed for the 876, it operates and handles the 50" just fine. I did a quick check of the major assemblys and with the exception of the knife and bar assmebly both SBM's share the same frame and gearbox part numbers. Sounds like you have a 42" sicklebar mower. Dave Share this post Link to post Share on other sites
stoneman 10 #4 Posted August 11, 2010 I used a flash light and a magnifying glass and confirmed that the spec. # is 7 1311, and it does measure exactly 42" from front tooth to back tooth. I wonder if it could have been miss-tagged at the factory. Or maybe the reason it's in such great shape is that the original 50" bar was damaged and replaced with a 42". :D Share this post Link to post Share on other sites
davedean 2 #5 Posted October 12, 2015 Any body know what the part number is for the knives that go on the 42" sickle bar? Share this post Link to post Share on other sites