Spi 34-500-9 Threaded Ring Gage M18 X 1.50 Class 6G No Go

Product Description

The SPI 34-500-9 is a No Go threaded ring gage designed to verify external metric threads to M18 x 1.50 specifications at a Class 6G tolerance. Machined from Oil Hardened Non-Shrinking Steel (OHNS), also referred to as tool steel, this single-ring gage provides the dimensional resistance and wear characteristics required for reliable thread inspection in production and quality-control environments. NPL traceability certification is included, making it suitable for use in shops and facilities where documented measurement traceability is required. Machinists, quality technicians, and inspection personnel use this gage to confirm that threaded components do not pass an out-of-tolerance condition.

This gage is used in machine shops, manufacturing facilities, and inspection departments where metric fastener threads must be verified against M18 x 1.50 Class 6G standards. The No Go function confirms that an externally threaded part does not exceed the maximum material condition for the specified tolerance class. It is a single-ring design, intended for use alongside a corresponding Go ring gage to complete a full pass-fail thread inspection routine. Applications include production line inspection of bolts, studs, and threaded shafts in automotive, industrial, and general mechanical manufacturing.

Key Features

• No Go ring gage verifies M18 x 1.50 external metric threads at Class 6G tolerance
• Oil Hardened Non-Shrinking Steel (OHNS) construction for dimensional stability and wear resistance
• NPL traceability certification included for use in documented quality systems
• Single-ring design for dedicated No Go inspection function
• Weighs 1 pound — compact enough for bench or floor-level inspection stations

Compatibility

Designed for inspection of externally threaded metric fasteners and components with M18 x 1.50 thread form at Class 6G tolerance per applicable metric thread standards.

Installation Notes

Threaded ring gages are handled and stored by quality technicians and inspection personnel, not installed in a mechanical system. Keep the gage clean and lightly oiled when not in use to prevent corrosion and maintain calibration integrity. Do not force the gage onto a threaded part — the No Go gage should not fully engage a conforming thread. Periodic re-calibration against NPL-traceable masters is recommended per your facility quality program.