How to measure internal groove diameter (BOWERS, XT3, Taechang Trading Corp) - YouTube
How to measure O-ring grooves, blind-hole corners, and undercuts - Novacam
Hammond & Co. Groove Gauge In Action, for measuring grooves in holes/bores - YouTube
ACiyD Electronic Inside Groove Caliper, Digital Caliper Measuring Tool, Large LCD Screen, Stainless Steel Vernier Caliper for Internal Groove Measurement (Size : 15-300 mm) (70) : Amazon.co.uk: Business, Industry & Science
Metric/ Inch Digital Electronic Vernier Caliper for Inside Internal Slot Groove Measurement - China Vernier Caliper, Digital Vernier Caliper | Made-in-China.com
Kroeplin H102 Mechanical Interna Groove Gauge, Measuring range 2,5 - 12,5 mm Scale interval 0,005 mm Measuring depth max. L: 12 mm
Double Jaw Internal Groove Caliper Inside Bore Caliper Groove Thickness Gauge Measuring Tools | ROK International