Press release #Automotive Aftermarket

New professional tool extends service life of high-quality Bosch M18 iridium spark plugs

Re-gapping tool from Bosch for exact readjustment of the electrode spacing between industrial spark plugs

  • Bosch develops professional tool for readjusting the electrode spacing
  • Only a few seconds required for exact adjustment of the recommended electrode spacing
  • Integrated force limiter prevents damage to electrodes during the bending process
Nico Krespach

Nico Krespach >


Karlsruhe – With its M18 iridium spark plugs, Bosch has established a new generation of industrial spark plugs which meet the increased thermal and mechanical demands of highly-charged stationary engines while offering a longer service life. With the new re-gapping tool developed by Bosch, users can exactly readjust the increased electrode gap caused by wear, thereby extending the service life of high-quality industrial spark plugs. Thanks to high-quality materials, modern manufacturing technology, and improved design, the new generation of industrial spark plugs offered by Bosch is very robust. For example, a new coating method and a laser-welding method patented by Bosch for iridium electrodes improve the durability of the electrodes.

Damage to spark plugs after adjustments without professional tools

Bosch uses iridium, an extremely erosion-resistant precious metal, for the electrodes in its high-quality M18 spark plugs. Nevertheless, the electrode gap of the spark plug increases as a result of wear during operation, which can result in misfires. For cost reasons, attempts are often made to re-gap the electrode spacing using the most basic tools. But without the appropriate tools, the ground electrode can be bent too far or even broken off. The electrode spacing is also easily set incorrectly or the spark plug damaged which can lead to longer periods required for servicing or unplanned downtimes.

Adjustment principle adopted from spark plug production

As a general rule, it is possible to readjust the electrode spacing of iridium M18 industrial spark plugs from Bosch. With the new re-gapping tool, the adjustment principle for electrode spacing used in production has been applied to a handy service tool. It makes it possible for users to exactly readjust the electrode spacing on industrial spark plugs within only a few seconds. Thanks to integrated force limitation, the re-gapping tool prevents either bending the ground electrode too far out or deforming the center electrode by applying too much pressure on the ground electrode.

The Automotive Aftermarket division (AA) provides the aftermarket and repair shops worldwide with modern diagnostic and repair-shop equipment and a wide range of spare parts – from new and exchange parts to repair solutions – for passenger cars and commercial vehicles. Its product portfolio includes products made as Bosch original equipment, as well as aftermarket-specific products and services developed and manufactured in-house. About 13,000 associates in more than 150 countries, as well as a global logistics network, ensure that spare parts reach customers quickly and on time. AA supplies testing and repair-shop technology, diagnostic software, service training courses, and information services. In addition, the division is responsible for the “Bosch Service” repair-shop franchise, one of the world’s largest independent chains of repair shops, with some 15,000 workshops, and more than 1,000 “AutoCrew” partners.

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The Bosch Group is a leading global supplier of technology and services. It employs roughly 421,000 associates worldwide (as of December 31, 2022). The company generated sales of 88.2 billion euros in 2022. Its operations are divided into four business sectors: Mobility, Industrial Technology, Consumer Goods, and Energy and Building Technology. As a leading IoT provider, Bosch offers innovative solutions for smart homes, Industry 4.0, and connected mobility. Bosch is pursuing a vision of mobility that is sustainable, safe, and exciting. It uses its expertise in sensor technology, software, and services, as well as its own IoT cloud, to offer its customers connected, cross-domain solutions from a single source. The Bosch Group’s strategic objective is to facilitate connected living with products and solutions that either contain artificial intelligence (AI) or have been developed or manufactured with its help. Bosch improves quality of life worldwide with products and services that are innovative and spark enthusiasm. In short, Bosch creates technology that is “Invented for life.” The Bosch Group comprises Robert Bosch GmbH and its roughly 470 subsidiary and regional companies in over 60 countries. Including sales and service partners, Bosch’s global manufacturing, engineering, and sales network covers nearly every country in the world. With its more than 400 locations worldwide, the Bosch Group has been carbon neutral since the first quarter of 2020. The basis for the company’s future growth is its innovative strength. At 136 locations across the globe, Bosch employs some 85,500 associates in research and development, of which nearly 44,000 are software engineers.

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