Item # RDJ304SM6, RDJ300 Inserts - Ring Locked w/ C´Bore Fine Internal and External Threads On Howmet Aerospace

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Unit of Measure

Insert Type	N/A Standard
Series	N/A RDJ300
Material Type	N/A 303 CRES
Material Specification	N/A ASTM A582 or AMS 5640
Heat Treat	N/A None
Finish	N/A Passivate per AMS2700
Lockring Howmet Part Number	N/A RLRR21SB6
Lockring Military Part Number	N/A MS51990-104P
Internal Thread Lock	N/A No
A - Internal Thread, Class 3B¹	N/A 0.1640-36 UNJF
B - External Thread	N/A 0.2500-28
B - External Thread - Pitch Diameter	N/A 0.2271-0.2286 in
B - External Thread - Minor Diameter	N/A 0.2014-0.2080 in
C - Length ±.015	N/A 0.380 in
D ±.015	N/A 0.250 in
E ±.005	N/A 0.047 in
F ±.005	N/A 0.166 in

Aluminum Step Drill Part Number²	N/A RCDC21-213
Magnesium Step Drill Part Number³	N/A RCADC21-213
Basic Tap Size⁴	N/A 0.2500-28 UNF
Wrench Part Number	N/A R1104W
Lockring Drive Tool Part Number	N/A R104D
Removal Drill Size⁵	N/A 19/64

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.
Unless otherwise specified dimensions are in inches & per ASME Y14.5M.
Mating lockring is not included with insert. It must be ordered separately.
For 1117 steel case hardened to 50-60 HRC, add suffix EO328 to lockring part number.
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.

Insert Type