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Unit of Measure

Insert Type

N/A Standard

Series

N/A RJ200

Material Type

N/A 4340 Steel (Alternate 4140 Steel)

Material Specification

N/A AMS-S-5000 or AMS-S-5625

Heat Treat

N/A 160-180 KSI UTS

Finish

N/A Cadmium plate per QQ-P-416, Type II, Class 3

Military Part Number

N/A MS51991-206

Lockring Rosan Part Number

N/A RLRR28SA8

Lockring Military Part Number

N/A AS51990-106P

Internal Thread Lock

N/A Yes
A - Internal Thread, Class 3B1 N/A 0.2500-28 UNJF

B - External Thread

N/A 0.3750-16

B - External Thread - Pitch Diameter

N/A 0.3347-0.3372 in

B - External Thread - Minor Diameter

N/A 0.2906-0.3011 in

C - Overall Length ±.015

N/A 0.500 in

D - Thread Length ±.015

N/A 0.330 in

E ±.015

N/A 0.170 in

F - Dia

N/A 0.305 in

G - Dia

N/A 0.291 in

H - Dia

N/A 0.257-0.267 in

J - Number of Teeth

N/A 20.000

K +2º -1º

N/A 102.000 º

L - Diameter +.007 -.002

N/A 0.345 in

M - Diameter +.005 -.004

N/A 0.316 in

N ±.015

N/A 0.110 in
Aluminum Step Drill Part Number2 N/A RCDC28-312
Magnesium Step Drill Part Number3 N/A RCADC28-312
Basic Tap Size4 N/A 0.3750-16 UNC

Wrench Part Number

N/A R1106W

Lockring Drive Tool Part Number

N/A R206D
Removal Drill Size5 N/A 5/16

N/A

  • The external thread has a special pitch diameter and minor diameter, which installs into an AS8879 Class 3B, FED-STD-H28/2 Class 3B, or National Class 3 tapped hole.
  • <3> Mating lockring is not included with insert. It must be ordered separately.
  • <4> For standard lenghts as shown in table, "C" overall length and "D" thread length applies. For non-standard lengths, "C" lengths is in 1/16 inch increments and "E" dimension applies in place of "D" dimension.
  • Unless otherwise specified dimensions are in inches & ASME Y14.5M.
  • When parent material surface is not flat or normal to axis of hole, provide a spotface for proper lockring entry.
  • Remove all burrs and sharp edges.

  • 1 AS8879 Internal Thread
  • 2 Step drills are designed for thru hole drilling. When used to drill a blind hole, it may be necessary to grind the drill to suit the depth required.
  • 3 Step drills are designed for thru hole drilling. When used to drill a blind hole, it may be necessary to grind the drill to suit the depth required.
  • 4 Taps are not supplied by Howmet.
  • 5 Removal drills are not supplied by Howmet.