Is BSF the same as Whitworth?
The British Standard Fine (BSF) thread has the same profile as the BSW thread form but was used when a finer pitch was required for a given diameter. There are other threads that are based upon the Whitworth thread form.
How do you identify Whitworth threads?
Whitworth Threads: Are a British standard symbolized by the letter W. Both types of threads offer a 5/8-11 thread size.
What is meant by Whitworth thread?
Definition of whitworth thread : a screw thread with V-shaped cut used chiefly in Britain for screws of larger sizes.
What is Whitworth measurement?
A Whitworth wrench is sized according to the diameter of the shank of the bolt, not the head. A 1/4 W (Whitworth) wrench is actually a bit larger than a 1/2″ American wrench—0.525″ to 0.500″. As if that wasn’t enough, in 1924 it was decided that the heads of the Whitworth bolts were too large, so they were down-sized.
How are Whitworth bolts measured?
The easiest way to identify a whitworth or BSF threaded bolt is to measure its diameter and check the thread rate (TPI or threads per inch) with a thread gauge and compare it to the charts below. BSW and BSF socket head screws use AF hex keys not metric.
Is UNF same as Whitworth?
Whitworth heads are NOT the same size as the equivalent UNC/UNF – they are larger. For this reason, it is imperative that a set of Whitworth wrenches are purchased before working on any antique British machinery. Otherwise, expect rounded-off heads and busted knuckles, trademarks of the careless craftsman.
What is the difference between Whitworth and UNC?
Whitworth threads can really upset the apple cart. They often have the same TPI as UNC threads (see thread tables), but use a different thread angle of 55 degrees, whereas UNC and UNF use 60 degrees.
When did Whitworth stop being used?
In the US, BSW was replaced when steel bolts replaced iron, but was still being used for some aluminium parts as late as the 1960s and 1970s when metric-based standards replaced the Imperial ones. American Unified Coarse (UNC) was originally based on almost the same Imperial fractions.
What size is a 3/8 spanner?
Imperial and Metric Spanner Sizes
| BOLT DIAMETER (INCHES) | AF SPANNER SIZE (INCHES) | SPANNER SIZE (MM) |
|---|---|---|
| 3/8 INCH | 9/16 INCH | 14.29 MM |
| 7/16 INCH | 5/8 INCH | 15.88 MM |
| 11/16 INCH | 17.46 MM | |
| 1/2 INCH | 3/4 INCH | 19.05 MM |