NGK Spark Plug Marking Symbols
| B | P | R | 5 | E | S | -11 |
|
Thread diameter A = 18mm B = 14mm C = 10mm D = 12mm BC = 14mm with 16mm hexagon
|
P = Projected insulator nose
U = Surface or semi-surface discharge |
R = Resistor |
Heat Range 2 = Hot 3 4 5 6 7 8 9 10 11 12 = Cold |
Thread reach E = 19.0mm H = 12.7mm |
S = Copper core Y = V-grooved with extra projection V = Gold/palladium centre electrode K = 2 ground electrodes T = 3 ground electrodes Q = 4 ground electrodes C = Short ground electrode P = Platinum tip F = Taper seat
|
Spark gap
9 = 0.9mm
-11 = 1.1mm
-13 = 1.3mm
-L = Half heat range
-N = Special ground electrode |
| BK…ISO size of BCP type, BCP type is 2.5mm taller from seat to top terminal
|
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| B | R | E | 5 | 2 | 7 | Y | -11 |
| Thread diameter
B = 14mm |
R = Resistor |
Thread reach
E = 19.0mm
|
Heat range |
Insulator nose projection
2 = 2.25mm
|
Spark position
7 = 7.0mm 9 = 9.5mm |
Y = V-grooved centre electrode |
-11 = Spark gap |