The Spiral Contractometer Method is ASTM Standard B636

Our Spiral Contractometer offers the advantage of a new geometry to solve problems related to an exposed center rod that allows deposition of the applied deposit to occur on the inside of the spiral (helix).  An interior deposit reversed the type of stress to a significant degree and on the inside of the spiral (helix).  An interior deposit reverses the type of stress to a significant degree and calculates erroneous data much greater that is commonly realized so interior masking is very necessary.  This design provides masking is sufficient for process control when using helices without an interior mask.  Also, it enables helices to be plated tip to tip so the plated surface area is the same for every spiral (helix). Guessing the surface area is not necessary.  Stainless steel inserts and 25% glass filled Teflon construction prevent thread damage.

The Advantages                                                       The Improvements

Accurate repeatable results                                        Thread stripping is prevented

Easy centering of the Helix                                         Reduced calibration wheel friction

Easy centering of the anode basket                           25% glass filled Teflon construction

Holes at helix ends- no slippage                                Inside spiral surface is shielded

Simple and rapid calculations in English/ Metric        Minimal  deposit on helix interior

Guess steps are eliminated                                        Precise scale to arrow view