Pernos Huck

The C50L® HuckBolt®
The
Fastening System
Strong and dependable lockbolts for heavy-duty,
vibration-intensive applications.

Grade 5 fasteners certified to meet or exceed
all ASTM A-325 standards.

F

or applications ranging from
railcar to mining equipment
manufacturing, C50L® HuckBolt®
fasteners from Alcoa Fastening
Systems offers superior vibration
resistance and overalldurability.
Heavy-duty applications demand
tough, reliable fasteners. And
extensive testing has demonstrated
that C50L HuckBolt fasteners meet
or exceed the performance of
torqued bolts in both shear and
tensile strength (with a longer
fatigue life). Value is built in, too.
Over the lifetime of your product,
the investment you make in the
quality of C50L HuckBolt fasteners
will pay foritself. While a single nut
and bolt may cost less than a C50L
fastener, you won’t find a more
accurate installation today or a more
reliable joint long term.

calibrating, maintaining, and
replacing tools are eliminated. And
unlike welding, installation of the
C50L does not require expensive,
highly experienced workers.
In addition, the C50L HuckBolt
fastening system is worker-friendly.It’s engineered to be installed
without torquing or multiple
impacts. Noise level is significantly
reduced. And your installation area
becomes quieter, less stressful, and
more productive. Because the
fasteners install without impact,
heat, or fumes, you’ll enjoy a safer,
cleaner work environment. And
ultimately, increase productivity and
decrease costly employee turnover.

Successful,consistent installations
Unlike threaded fasteners, the
C50L HuckBolt fastener gives you
consistent installation results with
virtually no rework. High costs of

1

The pin is inserted into the prepared
h ole and the smooth bore collar is
p laced on the pin


C50L® HuckBolt®

Swaged-on collar forms a permanent, vibration-proof connection

Initial long length of fastener enablespull-out of large gaps

Repeatable pre-load remains the same every time

2

The installation tool is applied to the pintail.
W hen the tool is activated, the jaws in the
n ose assembly pull on the pintail and the
n ose anvil pushes on the collar to remove
a ny gap.

3

The nose anvil starts to swage the collar
i nto the lockgrooves on the pin. Continued
s waging causes the collar tolengthen and
d evelop clamp.

4

When swaging of the collar into the lockgrooves is complete, the pintail separates from
the pin which completes the installation cycle.


C50L® Huckbolt®
C

C

A

A

90ϒ B

ref

B
min grip

min grip

D

E

90° Flush Head – C50L90

Round Head – C50LR
C

D

E

C

A

B

A

B

min grip

min grip

D

E

D

ELarge Truss Head – C50L30

Truss Head – C50LT

Fastener Dimensions
Round Head

Truss Head
C50LT

Large Truss Head
C50L30

90°Flush
Head

Dia.



A

B

C

B

C

B

C

B

C

1/2
5/8
3/4
7/8

(16)
(20)
(24)
(28)

0.515 - 0.493
0.642 - 0.617
0.768 - 0.741
0.895 - 0.866

59/64
1-9/64
1-3/8
1-19/32

5/16
25/6415/32
35/64

59/64
1-9/64
1-3/8
1-19/32

15/64
19/64
23/64
13/32

1-3/32
1-3/8



17/64
21/64



29/32
1-5/32
1-3/8
1-19/32

1/4
5/16
3/8
7/16

Collar Dimensions
Collar

Diameter

F

G

H

LC

1/2

0.515 - 0.540

0.800 - 0.765

0.645 - 0.610



5/8

0.650 - 0.665

1.010 - 0.970

0.875 - 0.845 33/4

0.775 - 0.790

1.180 - 1.165

0.960 - 0.930



7/8

0.910 - 0.935

1.375 - 1.345

J

K

1.113 - 1.083

1/2

0.515 - 0.535

0.807 - 0.793

0.746 - 0.716

0.156 - 0.094

1.031 - 0.969



5/8

0.650 - 0.665

1.010 - 0.970

0.959 - 0.929

0.187 - 0.125

1.281 - 1.218



3/4

0.775 - 0.790

1.200 -...