Internal Threading Away From The Chuck On A Steady Rest - Metric Threads Can't Use The Half-nuts Media

Single point internal threading to a blind shoulder in some strut tubes for a 1989 Buick Reatta. Had to thread away from the chuck to control the stopping point to a blind shoulder. Also had to cut these threads on a steady rest due to the distance from the chuck. When cutting metric threads on an imperial lathe you can't disengage the half-nuts so stopping quickly at a blind shoulder is not an option. Cutting away from the chuck eliminates the challenge and you can cut at decent a speed.

Cutting a 51mm x 1.5mm internal thread on a lathe at over 600 rpm in Aluminum to a blind shoulder is manageable if you cut them away from the chuck. I also cut these same threads in steel strut tubes at 380 rpm using a PM 1440TL lathe (Precision Matthews PM 1440TL).

Struts for a 1989 Buick Reatta are no longer available so the customer came up with a modified design to thread the original strut tubes and insert the strut from a Buick Regal locked in with a Nut.

Left handed SHARS boring bar with lay down threading inserts.
How to calculate bore diameter for metric threads?
How to calculate depth of cut when threading?
Using the Machinist Pro Calculator from www.cncdirt.com to determine your threading passes when cutting single point threads.

Thanks for watching!

Bud Beets
BladsesIIB Knives

www.BladesIIB.com