Spark plug cross reference from David Olesen
Thread size Thread reach SINO (Torch) Bosch ND Champion NGK Autolite
14mm 12.7mm
1/2"
E5C 
E6C 
E7C 
E5T 
E6TC 
E7TC  
E7RTC
W8AC 
W7AC 
W4AC 
W8BC 
W7BC 
W6BC
WR6BC
W16FS-U
W20FS-U
W22FS-U
W16FP-U
W20FP-U
W22FP-U
W22FPR-U
L9G  
L7  
L5
L95YC   
L92YC 
L87YC 
L82YC
RL82YC
B5HS
B6HS
B7HS
BP4HS
BP5HS
BP6HS
BP7HS
BPR7HS
425
275
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