2015Vests forum
Compatibility issues between Tiffen arms and Pro socket blocks on vests
What the thread found
- Tiffen arm pins do not fit smoothly into Pro socket blocks due to dimensional differences, with the hole becoming too tight near the end of insertion.
- The issue stems from historical tolerance differences between manufacturers, with differences measured in thousandths of an inch rather than larger amounts.
- Solutions include replacing the female socket block on the Pro vest with a Tiffen socket block, sanding down the male pin on the Tiffen arm, or having a machinist machine down the female socket block.
- Socket block replacement on vests requires only turning eight screws.
- The tolerance specifications have been consistent at plus or minus 0.0005 inches since 1986, with a nominal diameter increase of 0.001 inches implemented in October 1986.
Depends on
- The exact cause of the dimensional mismatch remains unclear and may relate to worn components or measurement variations from early production.
- Sanding the male pin makes that specific arm incompatible with other female socket blocks, whereas machining the female block allows compatibility with multiple arms.
- Titanium socket blocks may require special care if modification is attempted.
- This is described as a long-standing issue from early manufacturing days.