Example (note that not all 6 fields will always
be used, such as in BKR6EY):
| B | CPR | 6 | E | S | -11 |
| First box from example (B): |
| Letter | Thread Diameter |
| A | 18mm |
| B | 14mm |
| C | 10mm |
| D | 12mm |
| J | 12mm |
| Second box from example (C, P, R): |
| Letter | Construction |
| C | Hex size 5/8" |
| K | 5/8" projected tip (ISO) |
| M | Compact type |
| P | Projected insulator type |
| R | Resistor type |
| U | Surface or semi-surface discharge type |
| Z | Inductive resistor |
| Third box from example (6): |
| Heat Range
2 (Hot) <———> 12 (Cold) |
| Fourth box from example (E): |
| Letter | Thread Reach |
| E | 19mm (3/4") |
| F | Tapered seat |
| H | 12.7mm (1/2") |
| L | 11.2mm (7/16") |
| No symbol:
18mmø = 12mm reach 14mmø = 9.5mm (3/8") reach |
|
| Fifth box from example (S): |
| Letter | Firing End Construction |
| A | Special design |
| B | Special design for Honda CVCC |
| C | Low angle ground electrode |
| G | Fine wire nickel alloy center electrode |
| GV | Gold-palladium center electrode
Special construction of V-type Racing use |
| H | Partial thread |
| K | 2 ground electrodes for Toyota / BMW |
| L | Half heat range |
| LM | Compact type for lawn mower |
| M | 2 ground electrodes for Mazda rotary engine |
| N | Special side electrode |
| P | Premium platinum |
| Q | 4 ground electrodes |
| R | Special ground electrode |
| S | Standard 2.6mmø center electrode |
| T | 3 ground electrode |
| U | Semi-surface discharge |
| V | Fine wire gold-palladium center electrode |
| VX | High performance platinum |
| W | Tungsten electrode |
| X | Booster gap |
| Y | V-grooved center electrode |
| Z | Thick 2.9mmø center electrode |
| Sixth box from example (-11): |
| Number | Gap |
| -8 | 0.8mm (0.032") |
| -9 | 0.9mm (0.036") |
| -10 | 1.0mm (0.040") |
| -11 | 1.1mm (0.044") |
| -13 | 1.3mm (0.050") |
| -14 | 1.4mm (0.055") |
| -15 | 1.5mm (0.060") |
| -20 | 2.1mm (0.080") |