Item # M4, M-Series Non-Spacer Couplings On U.S. Tsubaki Inc.

The ATRA-FLEX® M-Series flexible couplings are designed to accommodate a wide range of industrial applications, offering a torque capacity up to 3,610,000 in-lbs and can handle shaft diameters up to 16 inches. These couplings feature a unique twist-and-lock ring that eliminates the need for fasteners or special tools, facilitating easy installation and maintenance. The rugged polyurethane insert effectively absorbs torsional shock and vibration while accommodating angular, parallel, and axial misalignment, thereby enhancing equipment longevity. Additionally, the couplings operate lubrication free, have no metal-to-metal contact and can withstand temperatures ranging from -60°F to 350°F. For applications requiring corrosion resistance, options include stainless steel components or a cost-effective nitrocarburized process known as OnyxShield™, as an alternative.

Unique twist-and-lock ring eliminates special tools or fasteners.
No lubrication is required.
Quick insert replacement, reducing maintenance cost and downtime.
Large torque capacity up to 3,610,000 in-lbs for a wide range of industrial applications.
Insert is the only wearing component with no metal-to-metal contact.
Polyurethane inserts are available in a range of hardness to meet most torsional stiffness and torque requirements.
Dampens torsional vibrations and absorbs shock loads.
Standard inserts have a temperature range from -60° to 250° Fahrenheit with high temperature inserts available up to 350°F.
OnyxShield™ couplings are available for enhanced corrosion and wear resistance.

Unit of Measure

Specifications | Insert Type Yellow | Insert Type Orange | Insert Type Red | Insert Type Green

Specifications

D1	N/A 7.600 in
G	N/A 6.700 in
MAXIMUM BORE	N/A 3.375 in
RSB	N/A 0.940 in
C1 (IDEAL DBSE)	N/A 0.300 in
L	N/A 3.200 in
D2	N/A 5.500 in
D3	N/A 6.400 in
J1	N/A 1.350 in
J2	N/A 3.250 in
K	N/A 3.100 in
E (GAP)	N/A 0.200 in
Weight with RSB hubs	N/A 36 lb
Max RPM Balanced G2.5 Standard	N/A 5,300
Max RPM Unbalanced Standard	N/A 3,600

Insert Type Yellow

Continuous Standard - Yellow	N/A 12,600 lb·in
Intermittent Standard - Yellow	N/A 21,000 lb·in
HP at 100 RPM Standard - Yellow	N/A 20 SF1
Temperature [Max] Standard - Yellow	N/A 250 ºF
Temperature [Min] Standard - Yellow	N/A -60 ºF
Durometer Standard - Yellow	N/A 60D

Insert Type Orange

Continuous - Orange	N/A 23,940 lb·in
Intermittent - Orange	N/A 39,900 lb·in
Temp Rating - Orange	N/A -20/250 ºF
Durometer - Orange	N/A 70D

Insert Type Red

Continuous - Red	N/A 10,710 lb·in
Intermittent - Red	N/A 17,850 lb·in
Temp Rating - Red	N/A 20/350 ºF
Durometer - Red	N/A 90A

Insert Type Green

Continuous - Green	N/A 6,143 lb·in
Intermittent - Green	N/A 10,238 lb·in
Temp Rating - Green	N/A -60/250 ºF
Durometer - Green	N/A 90A

Specifications

D1

G

MAXIMUM BORE

RSB

C1 (IDEAL DBSE)

L

D2

D3

J1

J2

K

E (GAP)

Weight with RSB hubs

Max RPM Balanced G2.5 Standard

Max RPM Unbalanced Standard

Insert Type Yellow

Continuous Standard - Yellow

Intermittent Standard - Yellow

HP at 100 RPM Standard - Yellow

Temperature [Max] Standard - Yellow

Temperature [Min] Standard - Yellow

Durometer Standard - Yellow

Insert Type Orange

Continuous - Orange

Intermittent - Orange

Temp Rating - Orange

Durometer - Orange

Insert Type Red

Continuous - Red

Intermittent - Red

Temp Rating - Red

Durometer - Red

Insert Type Green

Continuous - Green

Intermittent - Green

Temp Rating - Green

Durometer - Green