In reply to GrahamD:
> Err as long as I've climbed on SS the grades bore little relationship to the UK tech grade as part of the adjectival grade.
Trad tech grades and Sandstone top-rope grades may not have been equivalent in difficulty, but they were being used in the same way.
When doing the conversion in this book we came across routes of UK Tech 5a that spanned sport grades of 5/5b to 6a+. In the higher grades the range was even wider with a UK Sandstone tech of 6b being anything from 7a to 8a sport. This isn't incorrect use of the tech grade though since, on trad routes, UK Tech 6b can span E1/2 up to E8. But tech grades were never designed to be used on their own.
The measure of the worthiness of a grade is whether the climbers doing the hardest climbs use it to communicate the difficulty level to each other. On sandstone climbers doing the hardest routes have been using sport grades for years.
Alan