Delta 40-440 scroll saw spring replacements

Modified on 2018/08/22 09:11 by Joe — Categorized as: Restoration Topics

For those of you restoring a Delta 40-440 scroll saw with missing springs as I have recently done there are contemporary equivalents available.

The following springs are available at Century Spring Corp. Please refer to the following Vintage Machinery document for part/item numbers indicated below: http://vintagemachinery.org/pubs/detail.aspx?id=1529

The table's trunnion locking knob spring: Delta part #NCS-33 (item #90) can be replaced with: http://www.centuryspring.com/compression-spring-3253.html
The stop rod spring: Delta part #NCS-179 (item #25) can be replaced with: http://www.centuryspring.com/compression-spring-h-88.html
The air pump valve springs: Delta part #NSS-219 (item #109) can be replaced with: http://www.centuryspring.com/compression-spring-ii-86.html

There are other springs on this machine of course but I only needed the ones above. A word of caution when matching a spring.
Obviously the closer you get to the anatomical characteristics of the original spring the better. While the diameter, free length and wire size are the most obvious to duplicate, don't overlook the number of coils.
When the diameter, free length and wire size are matched, generally more coils in the free length yields a lighter load rating than less coils in the same amount of free length.
I found these things out while testing several versions of the 'same' spring on the air pump valves. A load rating much above .400 rendered the air pump almost worthless and .200 or less was best.