This section contains full size anchor nuts which are preferred over the reduced rivet spacing anchor nuts due to less chance of cracks forming between rivet holes and screw holes.
MS21047, K1000 self-locking 2 lug low height fixed anchor nut
K1000 is Alcoa fastening systems (Kaynar) number for similar anchor nut.
Options: ‘L’ – Dry film lubricated (most common)
‘-’ – Non lubricated
‘K’ – dimpled/countersunk holes for rivets
Current spec: NASM 21047 (still uses MS21047 for part number)
Common sizes
Dash number |
Thread |
Rivet spacing |
Height |
Rivet size |
06 |
6-32 (.138) |
.688 |
.171 |
3/32 |
08 |
8-32 (.164) |
.688 |
.250 |
3/32 |
3 |
10-32 (.190) |
.688 |
.250 |
3/32 |
4 |
¼-28 (.250) |
1.000 |
.281 |
3/32 |
5 |
5/16-24 (.3125) |
1.000 |
.328 |
1/8 |
6 |
3/8-24 (.250) |
1.000 |
.344 |
1/8 |
Examples: MS21047L3 is a 10-32 anchor nut lubricated
MS21047-3 is a 10-32 anchor nut not-lubricated
MS21047L3K is a 10-32 anchor nut lubricated dimpled rivet holes
MS21049, K1100 self-locking 2 lug low height fixed anchor nut countersunk screw hole
K1100 is Alcoa fastening systems (Kaynar) number for similar anchor nut.
Options: ‘L’ – Dry film lubricated (most common)
‘-’ – Non lubricated
‘K’ – dimpled/countersunk holes for rivets
Current spec: NASM 21049 (still uses MS21049 for part number)
Sizes available
Dash number |
Thread |
Rivet spacing |
Height |
Rivet size |
08 |
8-32 (.164) |
.688 |
.272 |
3/32 |
3 |
10-32 (.190) |
.688 |
.281 |
3/32 |
4 |
¼-28 (.250) |
1.000 |
.340 |
3/32 |
5 |
5/16-24 (.3125) |
1.000 |
.422 |
1/8 |
Examples: MS21049L3 is a 10-32 anchor nut lubricated
MS21049-3 is a 10-32 anchor nut not-lubricated
MS21049L3K is a 10-32 anchor nut lubricated dimpled rivet holes
MS21051, K2000 self-locking 1 lug low height fixed anchor nut
K2000 is Alcoa fastening systems (Kaynar) number for similar anchor nut.
Options: ‘L’ – Dry film lubricated (most common)
‘-’ – Non lubricated
‘K’ – dimpled/countersunk holes for rivets
Current spec: NASM 21051 (still uses MS21051 for part number)
Common sizes
Dash number |
Thread |
Rivet spacing |
Height |
Rivet size |
06 |
6-32 (.138) |
.312 |
.171 |
3/32 |
08 |
8-32 (.164) |
.312 |
.250 |
3/32 |
3 |
10-32 (.190) |
.312 |
.250 |
3/32 |
4 |
¼-28 (.250) |
.312 |
.281 |
3/32 |
5 |
5/16-24 (.3125) |
.312 |
.328 |
1/8 |
6 |
3/8-24 (.250) |
.312 |
.344 |
1/8 |
Examples: MS21051L3 is a 10-32 anchor nut lubricated
MS21051-3 is a 10-32 anchor nut not-lubricated
MS21051L3K is a 10-32 anchor nut lubricated dimpled rivet holes
MS21055, K3000 self-locking corner low height fixed anchor nut
K3000 is Alcoa fastening systems (Kaynar) number for similar anchor nut.
Options: ‘L’ – Dry film lubricated (most common)
‘-’ – Non lubricated
‘K’ – dimpled/countersunk holes for rivets
Current spec: NASM 21055 (still uses MS21055 for part number)
Common sizes
Dash number |
Thread |
Rivet spacing |
Height |
Rivet size |
06 |
6-32 (.138) |
.486 |
.171 |
3/32 |
08 |
8-32 (.164) |
.486 |
.250 |
3/32 |
3 |
10-32 (.190) |
.486 |
.250 |
3/32 |
4 |
¼-28 (.250) |
.707 |
.281 |
3/32 |
5 |
5/16-24 (.3125) |
.707 |
.328 |
1/8 |
6 |
3/8-24 (.250) |
.707 |
.344 |
1/8 |
Examples: MS21055L3 is a 10-32 anchor nut lubricated
MS21055-3 is a 10-32 anchor nut not-lubricated
MS21055L3K is a 10-32 anchor nut lubricated dimpled rivet holes
MS21059, F5000 self-locking 2 lug low height floating anchor nut
F5000 is Alcoa fastening systems (Kaynar) number for similar anchor nut.
Options: ‘L’ – Dry film lubricated (most common)
‘-’ – Non lubricated
‘K’ – dimpled/countersunk holes for rivets
Current spec: NASM 21047 (still uses MS21047 for part number)
Common sizes
Dash number |
Thread |
Rivet spacing |
Height |
Rivet size |
06 |
6-32 (.138) |
.688 |
.203 |
3/32 |
08 |
8-32 (.164) |
.688 |
.250 |
3/32 |
3 |
10-32 (.190) |
.688 |
.250 |
3/32 |
4 |
¼-28 (.250) |
1.000 |
.281 |
3/32 |
5 |
5/16-24 (.3125) |
1.000 |
.328 |
1/8 |
6 |
3/8-24 (.250) |
1.000 |
.344 |
1/8 |
Examples: MS21059L3 is a 10-32 anchor nut lubricated
MS21059-3 is a 10-32 anchor nut not-lubricated
MS21059L3K is a 10-32 anchor nut lubricated dimpled rivet holes
MS21061, F2000 self-locking 1 lug low height floating anchor nut
F2000 is Alcoa fastening systems (Kaynar) number for similar anchor nut.
Options: ‘L’ – Dry film lubricated (most common)
‘-’ – Non lubricated
‘K’ – dimpled/countersunk holes for rivets
Current spec: NASM 21061 (still uses MS21061 for part number)
Common sizes
Dash number |
Thread |
Rivet spacing |
Height |
Rivet size |
06 |
6-32 (.138) |
.312 |
.203 |
3/32 |
08 |
8-32 (.164) |
.312 |
.250 |
3/32 |
3 |
10-32 (.190) |
.312 |
.250 |
3/32 |
4 |
¼-28 (.250) |
.312 |
.281 |
3/32 |
5 |
5/16-24 (.3125) |
.312 |
.328 |
1/8 |
6 |
3/8-24 (.250) |
.312 |
.344 |
1/8 |
Examples: MS21061L3 is a 10-32 anchor nut lubricated
MS21061-3 is a 10-32 anchor nut not-lubricated
MS21061L3K is a 10-32 anchor nut lubricated dimpled rivet holes
