UNF UNIFIED NATIONAL FINE BUTTON DIES SUTTON

Sutton Tools manufactures high-quality UNF (Unified National Fine) button dies, designed specifically for cutting new male external threads or cleaning up existing threads on studs and bolts.

• 1/4" (Nominal Diameter): This is designed for a rod or bolt measuring exactly 1/4 of an inch (6.35 mm) in diameter.
• 28 TPI (Threads Per Inch): There are exactly 28 thread crests per inch along the length of the screw. Because 28 TPI is closely packed, it creates a shallow, tightly spun thread form.

• This indicates the standardized Imperial thread standard used primarily in North America and across Australian automotive, aerospace, and light engineering applications.
• A 1/4" UNF thread is considered a "Fine" thread (28 TPI), whereas a 1/4" UNC (Unified National Coarse) thread has fewer, larger teeth (20 TPI). Fine threads offer better vibration resistance and tighter clamping force.

• General Purpose / DIY Use: The tool is manufactured from high-carbon alloy steel.
• Material Compatibility: It is optimized for cutting threads into softer materials like brass, aluminum, copper, mild steel, and plastics.
• Limitations: It should not be used on hardened alloys or stainless steel, as the teeth will dull quickly. Manufacturer guidelines state that carbon alloy steel dies are not intended for precision, safety-critical, or aerospace structural threading.

• Form Factor: This is a circular, ring-shaped disc with internal cutting teeth and material clearance holes (flutes) to let metal shavings drop out.
• Standard Sizing: Sutton Tools produces this under the code M4150635 featuring a standard 1" Outer Diameter (OD), or under M4160635 featuring a 1-1/2" OD.
• Application: It sits tightly inside a matching 1" or 1-1/2" die stock handle or die guide. You chamfer the edge of your metal rod, apply cutting fluid, place the die flat over the rod, and rotate it clockwise by hand to cut your external fine threads.