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Manufacturing Facilities


Complete Manufacturing and Machining Facilities

Material Choice: Quality Starts Here

Diamond Engineering specialty fasteners are CNC machined in house using only the best quality materials. Purchased directly from the steel mill two alloys arebemployed to make the majority of fasteners and components. For items such as spacers and non critical fasteners 303XL alloy is used. A technologically advanced product that allows for superior machinability and holding precision part tolerances. Even before machining starts the tolerances of this material is better than most finished parts on the market today. Improvements of 50% over commercial ASTM standards for straightness and diameter plus perfect machining consistancy bar to bar insures quality parts from the first to last piece.

Manufacturing Facilities

 


 

Manufacturing Process: Performance & Consistant Quality


Performance and consistant quality is what every company strives for in it’s products. Diamond Engineering reaches these goals and beyond. Manufacturing our products from raw material to finished product in house using modern and hi-tech maching processes we are able to control all aspects of quality. Pictured here is our Mazak CNC Turning Center. All operations including thread rolling and forming of the bolt head can be done on one machine.

 

Thread Rolling in process

Thread Rolling in process

Forming a 12 Point head

Forming a 12 Point head

Robotics and Automation are being incorporated into the manufacturing process to enable lights out production.

Robotics and Automation are being incorporated into the manufacturing process to enable “lights out” production.

This illustration shows the difference in grain flow between a rolled thread, left, and a cut thread, right. Additional tensile strength and improved surface finish are inherent by-products of the thread rolling process.

This illustration shows the difference in grain flow between a rolled thread, left, and a cut thread, right. Additional tensile strength and improved surface finish are inherent by-products of the thread rolling process.


Virtually every fastener produced by Diamond Engineering has rolled threads as opposed to cut. Diamond Engineering chooses to use this method for several reasons. Increased accuracy, better surface finish, greater tensile, yield and shear strength. When roll threading, you are actually flowing and compressessing the grain of the material as opposed to cutting away the grain. By doing this you work harden and burnish the surface. The work hardened flank provides increased surface tensile, yield and shear strenght. Due to pressure deformation, a residual compressive stress system builds up at the thread root, which counter-acts tensile loading. When compared to a cut thread, the load capacity of the rolled thread is increased by up to 15%.



cross section

Cross section of Head Bolts showing deep socket for allen wrench. Parts are also marked in critical areas for Rockwell hardness testing. This is to confirm proper hardness throughout the entire bolt.

Gaging the Thread

 Precision thread rolling means precision gaging.Diamond Engineering uses Tri Roll thread gages to measure all fasteners we produce.This method allows the measurement of full profile, pitch diameter, best wire, minor diameter, major diameter and lead/flank angle with 1/10000” readings. Coventional Go and No-Go gages only tell you if the thread is good or not. You have no idea if you are on the high or low side of the tolerence. Diamond Engineering does not use this type of gaging. We use Tri Roll gages for machine setup and throughout manufacturing to insure consistant quality parts. Standard fasteners, especially button caps have shallow allen key holes that lead to “rounding out” of the hex over time even using  proper tightening specifications. All specialty socket style fasteners produced by Diamond Engineering are broached deeper than the ANSI/ASME standard calls for. For example the button cap style head bolts we manufacture has a key depth 20% deeper than the ANSI/ASME standard. This bolt has a torque specification of 40 lb.ft.. In our first test we were able to achive 115 lb. ft. of torque before falure. What was suprising is the fact that the allen key snapped in half and the bolt was still servicable. In subsequent tests at least 100 lb. ft. of torque was reached before any failure occured. In most cases it was the tool that failed not the internal hex of the bolt. Whether it is a critical engine application or an accessory cover we engineer safety and performance in each fastener we produce.

thread gaging

 


 

Secondary operation machining

Precision secondary operations are often needed for for many of the fasteners and components. Diamond Engineering is equiped to perform these secondary ops whether it be drilling cross holes in disc brake banjo bolts or milling slots in axle spacers.

 

 


 

Finish & Polishing

The final step after all the engineering, machining and testing is to produce the best finish in the industry. Testing equipment like this Mituytoyo surface roughness gage is used to insure that a consistant finish is achived throughout production. By measuring the part surface in millionth's of an inch, cutting insert wear can be monitored as well as the desired part finish prior to polishing. Pictured here are the profile evaluations of a head bolt. On the left is the rough surface left by the maching process. On the right is the finish after polishing.


 

All bolts are polished to a mirror finish. Second to none!

Just ask our customers.