Chip Load Formula
Known:
Feed Speed ------- 90 fpm.
No. of Teeth ------ 60
RPM --------------- 3600
Unknown:
Chip Load -------- ?
Chip Load is -----0.005"

Feed Speed (fpm) x 12 / No. of Teeth x rpm
= Chip Load

Tooth Quantity Formula
Known:
Feed Speed ----------- 90 fpm
RPM ------------------- 3600
Chip Load ------------ 0.005"
Unknown:
No of Teeth ------------- ?
No of Teeth is ---------- 60

Formula
Feeds speed (fpm) x 12 / Rpm x chip load = no. teeth

Feed Speed Formula
Known:
No. of Teeth ------- 60
RPM ----------------- 3600
Chip Load ---------- 0.005"
Unknown:
Feed speed ------------ ?
Feed Speed is --------- 90 fpm
Note: Feed Speed must be converted to inches. (90 x 12)

Rpm x no. teeth x chip load / (12.9inches per foot)
= FeedSpeed