NGK Replacement Spark Plugs — 6-Pack CMR7H (10mm thread, 12.7mm reach, gasket seat)

NGK CMR7H-6PK is a six-pack of genuine NGK replacement spark plugs designed to restore reliable ignition in small engines that use a 10 mm thread and a 12.7 mm reach.

These NGK spark plugs arrive new and bulk packed as OEM-quality replacements for equipment that specifies part number CMR7H-6PK. They are standard, solid-tip plugs with a 5/8-inch hex size and a gasket seat, engineered for everyday use in handheld and small power equipment. The listing includes six identical plugs and notes common cross-reference numbers so you can confirm fitment before installation.

How do these spark plugs match original equipment specs?

The CMR7H-6PK plugs are manufactured to NGK's production tolerances and mirror the documented dimensions of many original factory parts. Key measurements such as the 10 mm thread diameter and 12.7 mm reach align with the engines designed for this style of plug. They include a gasket seat and a solid tip configuration, which matches the mechanical interface and firing characteristics expected by many small-engine manufacturers.

• Hex size: 5/8 in for standard wrench access
• Reach: 12.7 mm (0.5 in) to fit specified combustion chambers
• Thread diameter: 10 mm to match engine threads
• Gasket seat and solid tip to maintain secure sealing and consistent spark

Which engines and brands are these plugs compatible with?

NGK provides cross-reference information so shoppers can compare the CMR7H-6PK with other manufacturer part numbers. The plug commonly replaces items from brands such as Champion and Homelite/Jacobsen and lists compatibility with some Redmax equipment. Always check your engine’s owner manual or the sellers’ fitment list to confirm compatibility before purchase.

• Replaces Champion RZ7C
• Cross-references Homelite/Jacobsen OEM numbers: 870217001, 870301002
• Matches NGK reference 3066 and Torch A8RTC interchangeably
• Frequently used in small handheld engines like those from Redmax

What should I expect during installation and routine maintenance?

Installing these plugs requires basic hand tools: a 5/8-inch spark plug socket or wrench and a torque wrench if available. Before tightening, ensure the plug threads and cylinder head threads are clean; snug the gasket seat to create a proper seal. For routine maintenance, inspect electrodes for wear, fouling, or damage and replace all plugs in a set if one shows advanced wear.

• Use a 5/8 in socket for removal and installation
• Clean threads and seat area before fitting to avoid cross-threading
• Replace plugs in matching sets to maintain balanced performance
• Check electrode condition and gap per equipment manual

Why buy a six-pack instead of single plugs?

Purchasing a six-pack like the CMR7H-6PK is cost-effective for owners of multiple tools or those who prefer having spare parts on hand. It ensures consistent replacement parts across similar engines and reduces the need to reorder frequently. Bulk packaging is practical for service shops, rental fleets, and households with several small-engine machines.

• Better value per plug than single purchases
• Convenient for multi-tool households or repair shops
• Ensures consistent part specs across replacements
• Bulk packing minimizes individual packaging waste

Who is this for: The NGK CMR7H-6PK six-pack is aimed at owners and technicians of small-engine equipment—like chainsaws, trimmers, blowers, and other handheld tools—that require a 10 mm thread, 12.7 mm reach spark plug with a gasket seat. It suits DIYers who maintain several machines, service professionals who need reliable OEM-equivalent parts, and anyone who prefers stocking spares for seasonal maintenance.