1/2"-20 tpi Fine NF-SAE Rethreading Die from 155 /per Qty. Add to Cart This item is currently on backorder, but you can still purchase it now and we'll ship as soon as more become available. 1/2" diameter NF-SAE (20 threads per inch) nut-sized hex thread-restoring die (3/4" across the flats) You can use same wrench or socket to remove nut and run rethreading die on bolt or stud Rethreading die will not crosscut or undercut the thread the way a cutting die will Black oxided MADE IN USA SKU:1/2FD-20