BG SPARK PLUGS
BG’s Iridium Electrode Spark Plugs Are Designed To Run Cooler, Last Longer, For Today’s Clean Burn Engines. . .
- Iridium electrodes resist erosion at high temperatures.
- Exceptional performance under the most demanding operating conditions.
- Models available to meet the requirements of most industrial engines.
Consistent long-term performance has established BG’s reputation for engineering excellence.

Plug Type | Thread Size | Thread Reach | Model | Heat Range | Shielding Thread | Resistor | Installed Height | Hex Size | Std. Gap |
Unshielded ![]() |
7/8″-18 | 5/8″ | RB212-1 | Medium | – | Yes | 2-11/32″ | 15/16″ | .015″ |
5/8″ | RB105-1 | Cold | – | Yes | 3-7/16″ | 15/16″ | .015″ | ||
1″ | RB114-1 | Cold | – | Yes | 3-1/16″ | 15/16″ | .015″ | ||
1/2″ | RB485-1 | Medium | – | Yes | 2-15/32″ | 7/8″ | .015″ | ||
Shielded ![]() |
7/8″-18 | 5/8″ | RB118SD | Cold | 3/4″-20 | Yes | 2-3/32″ | 15/16″ | .015″ |
1/2″ | RBH485SD | Cold | 3/4″-20 | Yes | 2-1/4″ | 7/8″ | .015″ | ||
13/16″ | BG341-1 | Medium | 3/4″-20 | Yes | 2-1/2″ | 7/8″ | .014″ |
All models have two iridium ground electrodes except:
– Model BG341-1 has a massive nickel electrode (3 prongs).
(BG Spark Plugs continued on page 51)