Vintage USSR Inside Micrometer Set 50-75mm CHIZ

Original Vintage Soviet Inside Micrometer Set 50-75 mm Manufacturer: CHIZ Chelyabinsk Tool Factory, USSR Standard: GOST 10-75 Condition: NOS New Old Stock / Never Used ITEM OVERVIEW Up for sale is a legendary, high-precision Soviet-made inside micrometer calibrated in metric system, 50mm to 75mm range. This is an original piece of industrial history, manufactured during the USSR era at the renowned CHIZ factory. The tool is in brand new, unused condition (New Old Stock). It is still covered in its original factory protective grease and wrapped in anti-corrosion paper inside its original vintage plastic case. WHAT IT IS USED FOR This inside micrometer is designed for ultra-precise internal measurements with 0.01 mm accuracy. It is perfect for: Measuring cylinder bores, engine blocks, and internal diameters. Checking deep internal recesses and parallel grooves. High-precision machining, lathe work, and vintage tool collections. HOW IT WORKS Select the appropriate extension rod from the kit depending on your target size. Screw the extension rod firmly onto the main micrometer head. Insert the tool into the bore, rotate the thimble until both anvils touch the walls, and rock it slightly to find the true center. Read the measurement by adding the base micrometer head size, the rod length, and the scale reading. PROS AND CONS OF THIS SOVIET TOOL PRO - Military-Grade Steel: Made from premium Soviet tool steel. Extension rods are incredibly rigid to prevent bending, and measuring faces are highly wear-resistant. PRO - Zero Electronics: Fully mechanical analog tool. It requires no batteries, won't fail in cold weather, and is completely resistant to shop oils and grime. PRO - Authentic Quality: Made in USSR tools are highly praised worldwide by machinists for their uncompromising, built-to-last durability compared to modern cheap alternatives. CON - Manual Reading: Requires basic knowledge of how to read a standard metric vernier scale (no digital LCD screen).