Locking vs Non-Locking Crownserts: What’s the Difference?

The core differences come down to the drive interface and the presence of an internal locking feature. 
Locking Crownserts use a 6-point drive and include an internal lock that generates prevailing torque on the male fastener. 
Non-locking Crownserts use a 4-point drive and have no prevailing-torque feature, offering low insertion torque and smooth serviceability.

When to Choose Each Version

  • Locking Crownserts (6-point drive): Best for assemblies exposed to vibration or cyclic loads. The internal lock—formed by 1–2 elliptical locking thread coils at the top of the insert—applies resistance to screw rotation, helping prevent loosening.
  • Non-locking Crownserts (4-point drive): Ideal where easy assembly/disassembly is required and prevailing torque is not necessary, e.g., frequent maintenance, soft-joint materials, or torque-sensitive components.

With many manufacturers, the driving and swaging operations require separate tools. 
Our installation tool combines both operations in one tool, improving consistency and reducing setup time.

Two Tools Combined into Efficient Installation Solution

Previously, both a swage tool and a drive wrench tool were required for the installation process. We have now combined these functions into one efficient hand-installation tool, simplifying the installation process and reducing the number of tools needed.

This new all-in-one solution enables faster, more practical, and user-friendly assembly while reducing handling time and the risk of installation errors.

Please refer to the table below for the corresponding new part numbers of the combined installation tools.

Imperial Locking Crownserts

Crownsert Installation Tool No°Old Swage Tool No°Old Drive Wrench No°
CSTL02 SR08 S-A SR08 W-A 
CSTL04 SR11 S-A SR11 W-A 
CSTL06 SR14 S-A SR14 W-A 
CSTL08 SR16 S-A SR16 W-A 
CSTL1024 SR19 S-A SR19 W-A 
CSTL1032 SR19 S-A 
SRQ19 S-A 		SR19 W-A 
CSTL420 SR25 S-A SR25 W-A 
CSTL428 SR25 S-A 
SRQ25 S-A 		SR25 W-A 
CSTL518 SR31 S-A SR31 W-A 
CSTL524 SR31 S-A 
SRQ31 S-A 		SR31 W-A 
CSTL616 SR37 S-A SR37 W-A 
CSTL624 SR37 S-A 
SRQ37 S-A 		SR37 W-A 
CSTL714 SR43 S-A SR43 W-A 
CSTL720 SR43 S-A 
SRQ43 S-A 		SR43 W-A 
CSTL820 SR50 S-A 
SRQ50 S-A 		SR50 W-A 
CSTL813 SR50 S-A SR50 W-A 
CSTL912 SR56 S-A SR56 W-A 
CTSL918 SR56 S-A SR56 W-A 
CSTL1011 SR62 S-A SR62 W-A 
CSTL1018 SR62 S-A SR62 W-A 
CSTL1210 SR75 S-A SR75 W-A 
CSTL1216 SR75 S-A SR75 W-A 
CSHTL02 SRW08 S-A SRW08 W-A 
CSHTL04 SRW11 S-A SRW11 W-A 
CSHTL06 SRW14 S-A SRW14 W-A 
CSHTL08 SRW16 S-A SRW16 W-A 
CSHTL1024 SRW19 S-A SRW19 W-A 
CSHTL1032 SRW19 S-A SRW19 W-A 
CSHTL420 SRW25 S-A SRW25 W-A 
CSHTL428 SRW25 S-A SRW25 W-A 
CSHTL518 SRW31 S-A SRW31 W-A 
CSHTL524 SRW31 S-A SRW31 W-A 
CSHTL616 SRW37 S-A SRW37 W-A 
CSHTL624 SRW37 S-A SRW37 W-A 
CSHTL714 SRW43 S-A SRW43 W-A 
CSHTL720 SRW43 S-A SRW43 W-A 
CSHTL813 SRW50 S-A SRW50 W-A 
CSHTL820 SRW50 S-A SRW50 W-A 
CSHTL912 SRW56 S-A SRW56 W-A 
CSHTL918 SRW56 S-A SRW56 W-A 
CSHTL1011 SRW62 S-A SRW62 W-A 
CSHTL1018 SRW62 S-A SRW62 W-A 
CSHTL1210 SRW75 S-A SRW75 W-A 
CSHTL1216 SRW75 S-A SRW75 W-A 

Imperial Non-Locking Crownserts

Crownsert Installation Tool No°Old Swage Tool No°Old Drive Wrench No°
CST02 SR08 S-A SR08-W4-A 
CST04 SR11 S-A SR11W4-A 
CST06 SR14 S-A SR14 W4-A 
CST08 SR16 S-A SR16 W4-A 
CST1024 SR19 S-A SR19 W4-A 
CST1032 SR19 S-A SR19 W4-A 
CST420 SR25 S-A SR25 W4-A 
CST428 SR25 S-A SR25 W4-A 
CST518 SR31 S-A SR31 W4-A 
CST524 SR31 S-A SR31 W4-A 
CST616 SR37 S-A SR37 W4-A 
CST624 SR37 S-A SR37 W4-A 
CST714 SR43 S-A SR43 W4-A 
CST720 SR43 S-A SR43 W4-A 
CST813 SR50 S-A SR50 W4-A 
CST820 SR50 S-A SR50 W4-A 
CST912 SR56 S-A SR56 W4-A 
CTSL918 SR56 S-A SR56 W4-A 
CST1011 SR62 S-A SR62 W4-A 
CST1018 SR62 S-A SR62 W4-A 
CST1210 SR75 S-A SR75 W4-A 
CST1216 SR75 S-A SR75 W4-A 
CSHT02 SRW08 S-A SRW08 W-A 
CSHT04 SRW11 S-A SRW11 W-A 
CSHT06 SRW14 S-A SRW14 W-A 
CSHT08 SRW16 S-A SRW16 W-A 
CSHT1024 SRW19 S-A SRW19 W-A 
CSHT1032 SRW19 S-A SRW19 W-A 
CSHT420 SRW25 S-A SRW25 W-A 
CSHT428 SRW25 S-A SRW25 W-A 
CSHT518 SRW31 S-A SRW31 W-A 
CSHT524 SRW31 S-A SRW31 W-A 
CSHT616 SRW37 S-A SRW37 W-A 
CSHT624 SRW37 S-A SRW37 W-A 
CSHT714 SRW43 S-A SRW43 W-A 
CSHT720 SRW43 S-A SRW43 W-A 
CSHT813 SRW50 S-A SRW50 W-A 
CSHT820 SRW50 S-A SRW50 W-A 
CSHT912 SRW56 S-A SRW56 W-A 
CSHT918 SRW56 S-A SRW56 W-A 
CSHT1011 SRW62 S-A SRW62 W-A 
CSHT1018 SRW62 S-A SRW62 W-A 
CSHT1210 SRW75 S-A SRW75 W-A 
CSHT1216 SRW75 S-A SRW75 W-A 

Metric Locking Crownserts

Crownsert Installation Tool No°Old Swage Tool No°Old Drive Wrench No°
CSTLM3 SRM0305S SRM0305W 
CSTLM4 SRM0407S SRM0407W 
CSTLM5 SRM0508S SRM0508W 
CSTLM6 SRM0610S SRM0610W 
CSTLM7 SRM0710S SRM0710W 
CSTLM8 SRM0812S SRM0812W 
CSTLM10 SRM1015S SRM1015W 
CSTLM12 SRM1215S SRM1215W 
CSTLM14 SRM1415S SRM1415W 
CSHTLM3 SRMW0305S SRM0305W 
CSHTLM4 SRMW0407S SRM0407W 
CSHTLM5 SRMW0508S SRM0508W 
CSHTLM6 SRMW0610S SRM0610W 
CSHTLM7 SRMW0710S SRM0710W 
CSHTLM8 SRMW0812S SRM0812W 
CSHTLM10 SRMW1015S SRM1015W 
CSHTLM12 SRMW1215S SRM1215W 
CSHTLM14 SRMW1415S SRM1415W 

Metric Non-Locking Crownserts

Crownsert Installation Tool No°Old Swage Tool No°Old Drive Wrench No°
CSTM3 SRM0305S SRM0305W 
CSTM4 SRM0407S SRM0407W 
CSTM5 SRM0508S SRM0508W 
CSTM6 SRM0610S SRM0610W 
CSTM7 SRM0710S SRM0710W 
CSTM8 SRM0812S SRM0812W 
CSTM10 SRM1015S SRM1015W 
CSTM12 SRM1215S SRM1215W 
CSTM14 SRM1415S SRM1415W 
CSHTM3 SRMW0305S SRM0305W 
CSHTM4 SRMW0407S SRM0407W 
CSHTM5 SRMW0508S SRM0508W 
CSHTM6 SRMW0610S SRM0610W 
CSHTM7 SRMW0710S SRM0710W 
CSHTM8 SRMW0812S SRM0812W 
CSHTM10 SRMW1015S SRM1015W 
CSHTM12 SRMW1215S SRM1215W 
CSHTM14 SRMW1415S SRM1415W 

Frequently Asked Questions

What is prevailing torque?

Prevailing torque is a built-in resistance to screw rotation. In locking Crownserts, 1–2 elliptical locking thread coils create a constant drag on the male fastener, improving vibration resistance.

Will locking Crownserts make service harder?

They require higher installation and removal torque by design. If frequent service is required and vibration is low, a non-locking Crownsert may be the better choice.