Starrett 51477 Center Gage 55 Degree Satin Chrome Steel

Product Description

The STARRETT 51477 is a 55-degree center gage machined from steel with a satin chrome coating. Center gages are precision layout and inspection tools used to check thread angles, set lathe tool bits to center, and verify the included angle of cutting tools. The 51477 features graduation markings from 1/32 to 1/14 inch, giving machinists a reliable reference for thread pitch and tool positioning tasks. The satin chrome finish reduces glare under shop lighting and provides basic corrosion resistance for shop environments. At 0.032 pounds, the gage is lightweight and easy to handle at the lathe or bench.

The STARRETT 51477 is suited for machine shops, toolrooms, and maintenance facilities where 55-degree thread forms are common. The 55-degree angle corresponds to Whitworth and BSP thread standards, making this gage appropriate for shops producing or servicing equipment built to British or older imperial thread specifications. Machinists and toolroom technicians use it when setting up engine lathes, checking thread form on finished workpieces, or grinding threading tool bits to the correct profile.

Key Features

• 55-degree included angle for Whitworth and BSP thread form verification
• Graduation range from 1/32 to 1/14 inch for pitch reference
• Satin chrome coated steel construction reduces glare and resists corrosion
• Lightweight at 0.032 pounds for easy one-hand use at the lathe
• Compact form factor fits in a tool apron or bench drawer

Compatibility

Designed as a general-purpose center gage for use with 55-degree thread forms on standard engine lathes and bench inspection setups.

Installation Notes

No installation is required for this hand tool. Machinists should ensure the lathe is powered down and the spindle is locked before using any gage against a mounted workpiece or tool bit. Handle the gage edges with care, as the precision ground faces can be damaged by impact or improper storage. Store flat in a protective sleeve or dedicated gage roll to preserve the ground surfaces.