Tr50×8 thread: 50 × 8 mm

Threads › Tr50×8

Tr50×8 is a Trapezoidal (Tr) thread: 50 mm major diameter, 8 mm pitch, 30° form.

Standard	Trapezoidal (Tr)
Major diameter	50 mm
Pitch	8 mm
Thread angle	30°
Minor diameter, bolt	41.5 mm
Minor diameter, nut	42 mm
Tap drill	Not listed. Check your tap maker's chart.
Usual class	7e bolt, 7H nut

Minor diameters worked out from the basic profile: major Ø − pitch − 0.5 mm (bolt) and major Ø − pitch (nut).

Open Tr50×8 in Benchsmith Add to order list

Measure it

Bolt: Measure across the crests of the bolt with the caliper jaws. Worn bolts read 0.1 to 0.3 under.

Nut or tapped hole: Measure across the tops of the threads inside the nut or hole with the inside jaws. That is the minor Ø. Worn or oversize holes read a little over.

Close in size, won't mate

2-4.5 UNCØ50.8 mm, 4.5 TPI
2-4 ACMEØ50.8 mm, 4 TPI

One size up or down

Tr44×7Ø44 mm (down)
Tr60×9Ø60 mm (up)

Got a bolt and no idea what it is? Measure the outside Ø and type it into Benchsmith → Find → Thread.