Locksmith calculators and spec references
Free calculators and reference charts for interchangeable cores and master key systems, built from published manufacturer specifications. Every number is sourced, and everything you enter stays in your browser.
Tools
- SFIC Pinning Calculator
Bottom, master, control and top pins for every chamber of an A2, A3 or A4 core.
Guides
- Master Key Systems: A Complete Guide for Property Managers
How master key systems work, what the levels mean, what to ask a locksmith, and how to keep a system secure as tenants and staff change.