Pinning Specifications & Space/Depth Matrix
Accurate pinning specifications, spacing, depth tolerances, and Maximum Adjacent Cut Specifications (MACS) are essential for cylinder rekeying, master key calculation, key decoding, and field forensic analysis.
This reference consolidates factory specifications across primary North American commercial, residential, and institutional locking systems.
Technical Terminology & Measurement Standards
When reading factory pinning charts and caliper measurements, industry standards utilize the following dimensional constants:
- Effective Plug Diameter (EPD): The outer diameter of the plug cylinder body. Standard commercial cylinders generally feature an EPD of 0.500" (1/2 inch), while padlocks and compact cylinders vary (.400" to .450").
- To First Cut (TFC): The exact distance measured from the reference datum point to the center of the first pin cut. For shoulder-stop keys, this is measured from the shoulder stop face. For tip-stop keys (e.g., BEST SFIC), this is measured from the tip of the key blade.
- Between Cut Centers (BCC): The center-to-center distance between consecutive cut positions along the blade.
- Maximum Adjacent Cut Specification (MACS): The maximum allowable numerical difference between two adjacent cuts. Exceeding MACS creates steep ramps that cause key insertion or withdrawal binding and rapid blade wear.
- Root Cut Angle & Flat Width: The angle of the cutting wheel V-notch (typically 90 to 100 degrees) and the flat width at the bottom of the cut (typically .030" to .045").
Manufacturer Space & Depth Specifications Matrix
All dimensions are documented in decimal inches.
| Manufacturer | Pin Dia. | Increment | Depths | MACS | Root Cut Angle | Flat Width | Stop Type | First Cut (TFC) | Spacing (BCC) |
|---|---|---|---|---|---|---|---|---|---|
| Schlage Classic | .115" | .015" | 0–9 (.335"–.200") | 7 | 100° | .031" | Shoulder | .231" | .156" |
| Kwikset | .115" | .023" | 1–6 (.329"–.214") | 4 | 90° | .050" | Shoulder | .247" | .150" |
| Yale Standard | .115" | .019" | 0–9 (.320"–.149") | 4–5 | 90° | .034" | Shoulder | .214" | .150" |
| Sargent | .115" | .020" | 1–9 (.330"–.170") | 7 | 90° | .050" | Shoulder | .215" | .156" |
| Arrow | .115" | .014" | 0–9 (.324"–.198") | 7 | 90° | .052" | Shoulder | .264" | .155" |
| Master Lock (Standard) | .093" / .115" | .015" | 0–7 (.285"–.180") | 4 | 90° | .040" | Shoulder | .185" | .125" |
| American Lock | .093" | .015" | 1–8 (.286"–.181") | 5 | 90° | .040" | Shoulder | .160" | .125" |
| Corbin Russwin (System 70) | .108" | .014" | 1–6 (.322"–.252") | 3 | 90° | .054" | Shoulder | .250" | .156" |
| Weiser | .115" | .018" | 0–9 (.344"–.182") | 5 | 90° | .047" | Shoulder | .227" | .156" |
| Weslock | .115" | .015" | 0–9 (.340"–.205") | 4 | 90° | .045" | Shoulder | .228" | .153" |
| BEST SFIC (A-2 System) | .108" | .0125" | 0–9 (.318"–.206") | 9 | 90° | .025" | Tip | .105" (Tip) | .150" |
| BEST SFIC (A-3 System) | .108" | .018" | 0–6 (.318"–.210") | 6 | 90° | .025" | Tip | .105" (Tip) | .150" |
| BEST SFIC (A-4 System) | .108" | .021" | 0–5 (.318"–.213") | 5 | 90° | .025" | Tip | .105" (Tip) | .150" |
Detailed Manufacturer Pin Charts
1. Schlage Classic (.115" Pin Diameter)
- Root Depths (0–9):
0: .335" | 1: .320" | 2: .305" | 3: .290" | 4: .275" | 5: .260" | 6: .245" | 7: .230" | 8: .215" | 9: .200" - Bottom Key Pins (Lengths):
#0: .165" | #1: .180" | #2: .195" | #3: .210" | #4: .225" | #5: .240" | #6: .255" | #7: .270" | #8: .285" | #9: .300" - Master Split Pins (Thickness):
#2: .030" | #3: .045" | #4: .060" | #5: .075" | #6: .090" | #7: .105" | #8: .120" | #9: .135" - Top Driver Pins:
Standard sizes: #1 (.165"), #2 (.180"), #3 (.195"), #4 (.210"), #5 (.235") - Factory Notes:
Schlage pin bittings index progressively down into the key blade. The effective sum of the bottom pin, master pin(s), and driver pin is balanced against the cylinder bible depth to maintain equal spring tension across chambers.
2. Kwikset Standard (.115" Pin Diameter)
- Root Depths (1–6):
1: .329" | 2: .306" | 3: .283" | 4: .260" | 5: .237" | 6: .214" - Bottom Key Pins (Lengths):
#1: .172" | #2: .195" | #3: .218" | #4: .241" | #5: .264" | #6: .287" - Master Split Pins (Thickness):
#1: .023" | #2: .046" | #3: .069" | #4: .092" | #5: .115" - Top Driver Pins:
Standard driver length: .180" (regular flat spool / standard spool drivers). - Factory Notes:
Large increment of .023" makes Kwikset cylinders more forgiving to sloppy cuts, but results in a restrictive MACS of 4 to prevent steep cut transitions.
3. BEST Small Format Interchangeable Core (A-2 System)
- Pin Diameter: .108"
- System Increment: .0125"
- Root Depths (0–9):
0: .3187" | 1: .3062" | 2: .2937" | 3: .2812" | 4: .2687" | 5: .2562" | 6: .2437" | 7: .2312" | 8: .2187" | 9: .2062" - Bottom Key Pins (0–9):
#0: .0750" | #1: .0875" | #2: .1000" | #3: .1125" | #4: .1250" | #5: .1375" | #6: .1500" | #7: .1625" | #8: .1750" | #9: .1875" - Master & Control Pins (2–19):
Numbered directly by their dimensional build in increments of .0125" (e.g., #2 = .0250", #3 = .0375", #10 = .1250", #19 = .2375"). - Top Driver Pins (2–9):
Selected based on the total stack calculation. - Stack Constant: In the A-2 system, every chamber stack (Key Pin + Master Pin + Control Pin + Driver Pin) must total exactly 23 steps (.2875").
4. American Lock (.093" Pin Diameter)
- Root Depths (1–8):
1: .286" | 2: .271" | 3: .256" | 4: .241" | 5: .226" | 6: .211" | 7: .196" | 8: .181" - Bottom Key Pins: Serrated pins standard across most factory pinning.
- Top Drivers: Combination of serrated spool and serrated standard drivers designed to defeat raking and tension-induced overset detection.
- Factory Notes: Uses the smaller .093" pin diameter typical of high-tolerance padlocks. The spacing between cuts is .125" with a .160" first-cut distance.
5. Sargent (.115" Pin Diameter)
- Root Depths (1–9):
1: .330" | 2: .310" | 3: .290" | 4: .270" | 5: .250" | 6: .230" | 7: .210" | 8: .190" | 9: .170" - Increment: Uniform .020" depth steps.
- Key Pins: Hollow brass pins numbered 1 through 9.
- Factory Notes: MACS is 7. Generous increment and wide root flat (.050") make Sargent systems exceptionally smooth in commercial applications.
6. Yale Standard (.115" Pin Diameter)
- Root Depths (0–9):
0: .320" | 1: .301" | 2: .282" | 3: .263" | 4: .244" | 5: .225" | 6: .206" | 7: .187" | 8: .168" | 9: .149" - Increment: .019" step size.
- MACS: 4 or 5 depending on cylinder age and keyway warding profile.
Metallurgy & Pin Material Specifications
Pin composition impacts wear rates, resistance to impressioning, and thermal bypass behavior. Below are standard engineering characteristics for lock hardware alloys:
| Metal / Alloy | Temper / Form | Rockwell Hardness | Yield Strength (ksi) | Yield Strength (MPa) | Ductility Rating | Typical Application |
|---|---|---|---|---|---|---|
| Cartridge Brass (70/30) | 1/4 Hard | 55 HRB | 40 ksi | 276 MPa | Low (1) | Standard key pins, master split wafers |
| Nickel Silver (65-18) | 1/8 Hard | 60 HRB | 35 ksi | 241 MPa | Medium (3) | High-wear key blanks, commercial key pins |
| Stainless Steel (304) | Temper Pass | 88 HRB | 30 ksi | 207 MPa | Moderate (2) | Padlock shackle locking dogs, anti-drill pins |
| Phosphor Bronze | 1/2 Hard | 78 HRB | 55 ksi | 379 MPa | Medium (3) | Cylinder springs, tumblers |
| Low Carbon Steel | Cold Rolled | 60 HRB | 25 ksi | 170 MPa | Moderate (2) | Spool and mushroom driver pins (plated) |
Practical Rekeying & Forensic Rules
- Master Wafer Limiting: Never insert more than three shear lines per chamber (maximum of two master wafers per pin stack). Excessive master wafers weaken the cylinder to single-pin picking and increase the risk of cross-keying and phantom key generation.
- Adjacent Step Limits: Always verify cut progressions against the manufacturer MACS before cutting replacement operating or master keys.
- Tip Contact Variations: On cylinders where the key tip rests beneath the final chamber (such as Schlage and Arrow factory blanks), note that the tip profile can act as a partial cut if cut spacing or shoulder stop wear shifts the key deeper into the plug.
Authoritative Manufacturer & Public Domain References
Primary engineering sources, factory service manuals, and open technical standards verifying the dimensional data in this matrix:
- LAB Security Systems Pin Specifications & Universal Charts
The industry benchmark for universal cylinder repinning, specifying .115" standard commercial and .108" Small Format Interchangeable Core (SFIC) pin dimensions, colour-coding conventions, and gauge charts. - Allegion Schlage Service Manuals & Key Systems Guides
Official Allegion technical manuals covering Schlage Classic, Everest, and Primus cylinders, including factory space, depth, and rekeying tolerances. - Corbin Russwin Cylinder Manual (Archived via Internet Archive)
Comprehensive factory manual detailing Corbin Russwin combinating rules, System 70, Pre-System 70, interchangeable cores, and master key bitting specifications. - dormakaba BEST A2 System Technical Service Manual (Doc T61803)
The foundational factory engineering manual defining the BEST A-2 Small Format Interchangeable Core pinning standard, mathematical stack rules, and key cutting limits. - Sargent Lock Cylinders & Key Systems Catalog
ASSA ABLOY technical publication documenting Sargent conventional and LFIC pin lengths, spring chambers, and bitting specifications across all factory keyway families. - Master Lock Commercial & ProSeries Technical Manual (Doc 7000-0031)
Official service manual detailing Master Lock commercial pin-tumbler cylinder specifications, Edge keying, and rekeying procedures. - Kwikset Cylinder Re-Keying & SmartKey Security Documentation
Factory guide documenting .023" step increments, plug follower procedures, and gauge depths for classic Kwikset pin-and-tumbler deadbolts and key-in-knob cylinders. - ALOA Security Professionals Association Technical Resources
Standardized terminology (EPD, TFC, BCC, MACS) and master keying educational standards published by the Associated Locksmiths of America.