Nut, Self-Locking, Castellated, Hexagon, 250 °F, Non-Metallic Insert, from MS17825 Rev. J. Every row below is transcribed from the standard and has its own link.
MS17825 at a glance
MS17825Engineering drawing · dimensions in inches
Specification
Item
Value
Type
Self-locking castellated nut
Material
Steel: UNS G11370 (AISI 1137) per AMS 5024; UNS G41300 (AISI 4130) per AMS 6348; UNS G87400 (AISI 8740) per AMS 6322, 6323, 6325, 6327 and 6358. Insert: nylon.
Strength
Ultimate tensile strength per table (e.g. 3,500 lb min for -4)
Locking
Non-metallic (nylon) insert
Item
Value
Max. temperature
250 °F
Finish
Cadmium plated per SAE-AMS-QQ-P-416, Type II, Class 2.
Procurement
NASM25027
Status
Active. Rev. J (27 Jun 2011) reactivates the standard after 5 Feb 2004; may be used for new and existing designs and acquisitions. Supersedes MS17825H (5 Feb 2004).
Dimensions by size
Dimension, in
.1900-32 UNJF-3B
.2500-28 UNJF-3B
.3125-24 UNJF-3B
.3750-24 UNJF-3B
.4375-20 UNJF-3B
.5000-20 UNJF-3B
.5625-18 UNJF-3B
.6250-18 UNJF-3B
.7500-16 UNJF-3B
.8750-14 UNJF-3B
1.0000-12 UNJF-3B
1.1250-12 UNJF-3B
1.2500-12 UNJF-3B
A — Overall height
.265 – .235
.296 – .266
.343 – .313
.421 – .391
.468 – .438
.578 – .548
.624 – .594
.734 – .704
.828 – .798
.921 – .891
1.015 – .985
1.171 – 1.141
1.265 – 1.235
B — Width across flats
.376 – .367
.439 – .430
.502 – .492
.564 – .553
.690 – .679
.752 – .741
.877 – .865
.940 – .928
1.064 – 1.052
1.252 – 1.239
1.440 – 1.427
1.627 – 1.614
1.815 – 1.801
C — Width across corners, min
.410
.482
.552
.622
.766
.837
.978
1.051
1.191
1.403
1.615
1.825
2.038
D — Diameter D at the bearing face, max (see drawing)
.215
.275
.338
.400
.463
.525
.587
.650
.795
.900
1.025
1.150
1.275
G — Dimension G (see drawing)
.032 – .006
.036 – .007
.042 – .008
.050 – .010
.050 – .010
.050 – .010
.055 – .012
.055 – .012
.063 – .014
.072 – .016
.083 – .018
.083 – .018
.083 – .018
J — Dimension J (see drawing)
.125 – .105
.141 – .121
.188 – .168
.235 – .215
.282 – .262
.375 – .355
.406 – .386
.484 – .464
.578 – .558
.672 – .652
.766 – .746
.828 – .808
.891 – .871
K — Slot width
.108 – .078
.108 – .078
.108 – .078
.155 – .125
.155 – .125
.155 – .125
.187 – .157
.187 – .157
.187 – .157
.187 – .157
.187 – .157
.187 – .157
.187 – .157
L — Dimension L, min (see drawing)
.110
.125
.172
.218
.265
.359
.390
.468
.562
.656
.750
.844
.938
M — Washer face diameter (ØM)
.376 – .355
.439 – .418
.502 – .480
.564 – .543
.690 – .675
.752 – .737
.877 – .862
.940 – .925
1.064 – 1.049
1.252 – 1.237
1.440 – 1.425
1.627 – 1.612
1.815 – 1.800
R — Dimension R, max (see drawing)
.035
.035
.035
.053
.053
.053
.062
.062
.062
.062
.062
.062
.062
Maximum – minimum as tabulated in MS17825 Rev. J; letters as on the standard's drawing.
Use at 250 °F and below in applications where slotted or castellated nuts are approved; where this conflicts with any limitation on self-locking nuts cited in NASM33588, this standard takes precedence. Install per NASM33540.
Performance per NASM25027 except: tabulated ultimate tensile strength; vibration per NASM1312-7 (30,000 cycles) using the assembly torques in Table I for one seated cycle; locking torque values apply for one cycle at room temperature only.
Opposite slots must coincide within .005 and the slot axis must be within .005 of the thread pitch-diameter axis. Washer face, chamfer or radius relief optional within the 30° ±5° angle and ØM limitations.
For design features this standard takes precedence over the procurement document. Surface texture 125 microinches (ASME B46.1).
Dimensions in inches. Break all sharp edges and remove burrs.
