Custom Carbon Steel Grip Plug for Aerospace Application

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Carbon Steel Grip Plug

This featured grip plug is a critical aerospace part and is composed of 4140 stainless steel that was heat treated to 32-38 HRC. To manufacture the insert, a variety of CNC Swiss Turning processes were applied. Using a SR-32J Star Swiss type lathe with live tooling, we turned each side and turned the start of the lead thread to a chamfer of .06 x .45 degree with the M14 x 2.0 for the major diameter and pitch diameter, and with a thread relief having 2 radii of .060". Next, using the machine's y-axis capability with live tooling, we milled two .670" wrench flats into the stem. Throughout the machining process we maintained tight tolerances of +.001"/-.005", with features on a common axis to be GD&T run-out of .010" max. To conduct inspection we relied on an OGP touch probe and a vision system CMM, as well as micrometers, a custom thread gage, a drop gage, and a digital optical comparator.

The final Grip Plug featured .875" round bar stock, with a .786" outside diameter and a thread relief diameter of .450". We then labeled each carton with part and lot numbers, as well as the quantity. Packaging was limited to 50 parts per box, in accordance with aerospace bag and tag requirements. Included in each order was a raw material certification, complete with chemical and mechanical properties, and quality control verification. The project took 4 to 6 weeks to complete, and was then shipped to our PMA client for use in the aerospace industry.

Specifications for the Carbon Steel Grip Plug

Capabilities Applied/Processes	Swiss Machining Opposite ends of the same part can be machined simultaneously. Inspection
Equipment Used to Manufacture Part	Star SR-32J Swiss CNC Lathe w/ Live tooling OGP Touch Probe and Vision System CMM
Overall Part Dimensions	.875" Round Bar Stock O.D .786" .450" thread relief.
Tightest Tolerances	+001"/-.005" Features on a common axis to be GD&T run-out of .010" max
Material Used	4140 Stainless Steel
Max Material Finish	63 RMS
Typical Machining Operations	CNC Machining: Set up On Lathe Turn Side 1 Turn Side 2: start of the lead thread to a chamfer of .06 x .45 degree with the M14 x 2.0 for the major diameter and pitch diameter, with a thread relief having 2 radius of .060". Thread relief having 2 radii of .060" Mill wrench flats: Two .670" wrench flats centered 180 Degrees Inspection: Inspected using: CMM Micrometers Custom Thread Gage Drop Gage Digital Optical Comparator Packaging: Packaged to GMMCO Standards Paperwork Includes: Raw Material Certification w/ Chemical & Mechanical Properties All paper work is Stamped w. QC Inspector Stamp Packaging Slip 50 Parts Max. Per Box 40 Lbs Max. Per Box Box Size 12"x10"x6" Each carton To be Labeled w/ Part Number, Lot Number, and Quantity
Estimated Part Weight	¼ lbs
Industry for Use	Aerospace
Delivery Time	4-6 Weeks
Standards Met	Customer supplied print, 2D Auto CAD Drawing
Product Name	Custom Grip Plug