STF Models

Features

Specifications

Structure and Materials

Downloads

Excellent damping performance

Damping performance exceeds that of metal disc spring couplings, easily suppressing resonance, which can be a concern with stepping motors.

Shaft reaction force is reduced

Shaft reaction force caused by misalignment is greatly reduced by a laminated element construction that sandwiches hard rubber with soft rubber in the elastic component. This also greatly lessens the load on bearings and the like.

Simple, reliable, no backlash

Since the clamp method is used to couple to the shaft, mounting can be completed by tightening one bolt each on left and right.Clamp hubs are strong against vibration and shocks, couplings are reliable, and there is no backlash.

[Specifications]

Model	Torque		Misalignment			Max. rotation speed ［min^-1］	Torsional stiffness ［N・m/rad］	Moment of inertia ［kg・m²］	Mass ［kg］
Model	Nominal ［N・m］	Max. ［mm］	Parallel ［mm］	Angular ［°］	Axial ［mm］	Max. rotation speed ［min^-1］	Torsional stiffness ［N・m/rad］	Moment of inertia ［kg・m²］	Mass ［kg］
STF-013SA1	0.5	1	0.15	1.5	±0.2	10000	15	0.11×10^-6	0.004
STF-016SA1	1	2	0.15	1.5	±0.2	10000	27	0.31×10^-6	0.009
STF-019SA1	1.5	3	0.15	1.5	±0.2	10000	38	0.70×10^-6	0.013
STF-024SA1	2.5	5	0.15	1.5	±0.2	10000	127	1.89×10^-6	0.023
STF-029SA1	4	8	0.2	1.5	±0.3	10000	201	4.40×10^-6	0.034
STF-034SA1	6	12	0.2	1.5	±0.3	10000	371	9.77×10^-6	0.056
STF-039SA1	8.5	17	0.2	1.5	±0.3	10000	485	21.13×10^-6	0.091
STF-044SA1	15	30	0.2	1.5	±0.3	10000	996	37.34×10^-6	0.12
STF-056SA1	30	60	0.2	1.5	±0.3	10000	2075	125.5×10^-6	0.251

*Check the Max. Torque for the Shaft Diameter list as there may be limitations on the standard and maximum torque caused by the holding power of the coupling shaft section.

*The max. rotation speed values do not take into account dynamic balance.

*The static torsional stiff ness values are analysis values for the element taken at a temperature of 20°C at maximum bore diameter.

*The moment of inertia and mass are measured for the maximum bore diameter.

[Dimensions]

Model	d1, d2[mm]		D[mm]	L[mm]	LF[mm]	S[mm]	A[mm]	C[mm]	M Quantity-Nominal dia.	Tightening torque [N･m]
Model	Min.	Max.	D[mm]	L[mm]	LF[mm]	S[mm]	A[mm]	C[mm]	M Quantity-Nominal dia.	Tightening torque [N･m]
STF-013SA1	3	5	13	18	6	6	3.9	2	1-M1.6	0.23～0.28
STF-016SA1	3	6	16	22	7.5	7	4.8	2.5	1-M2	0.4～0.5
STF-019SA1	3	8	19	25	9	7	5.8(6)	3.15	1-M2.5(M2)	1.0～1.1(0.4~0.5)
STF-024SA1	5	10	24	27	9	9	8.7	3.15	1-M2.5	1.0～1.1
STF-029SA1	5	14	29	30	10	10	11	3.3	1-M2.5	1.0～1.1
STF-034SA1	5	16	34	34	12	10	12.5	3.75	1-M3	1.5～1.9
STF-039SA1	6	19	39	41	15.5	10	14	4.5	1-M4	3.4～4.1
STF-044SA1	8	24	44	48	15.5	17	17	4.5	1-M4	3.4～4.1
STF-056SA1	8	30	56	60	20.5	19	22	6	1-M5	7.0～8.5

*The nominal diameter for the clamp bolt M is equal to the quantity - the nominal diameter of the screw, where the quantity is for a hub on one side.

*The values in ( ) of the STF-019, d1 or d2 is the value in the case of ø8mm.

*The escape in the internal diameter of the element is equal to dimension d2 (large diameter) plus ø0.9 mm.

* The rated dimension tolerance for countershafts is h7 class.

[Standard bore diameter]

Model	Standard bore diameter d1, d2 ［mm］
Model	3	4	5	6	6.35	7	8	9	9.525	10	11	12	13	14	15	16	17	18	19	20	22	24	25	28	30
STF-013SA1	●	●	●
STF-016SA1	●	●	●	●
STF-019SA1	●	●	●	●	●	●	●
STF-024SA1			●	●	●	●	●	●	●	●
STF-029SA1			●	●	●	●	●	●	●	●	●	●	●	●
STF-034SA1			●	●	●	●	●	●	●	●	●	●	●	●	●	●
STF-039SA1				●	●	●	●	●	●	●	●	●	●	●	●	●	●	●	●
STF-044SA1							●	●	●	●	●	●	●	●	●	●	●	●	●	●	●	●
STF-056SA1							●	●	●	●	●	●	●	●	●	●	●	●	●	●	●	●	●	●	●

*The bore diameters in the boxes marked by [●] are used as standard bore diameters.

*Check the table for information on max. torque for the shaft diameter as there may be limitations on the standard and maximum torque determined by the holding power of the coupling shaft section depending on the bore diameter used.

[Max. torque for the shaft diameter]

Model	Standard bore diameter[mm] and max. torque for the shaft diameter[N･m]
Model	3	4	5	6	6.35	7	8	9	9.525	10	11	12	13	14	15	16	17	18	19	20	22	24	25	28	30
STF-013SA1	0.10	0.25	0.40
STF-016SA1	0.5	0.6	0.7	0.8
STF-019SA1	0.8	1.2	1.6	1.9	1.9	2.3	0.8
STF-024SA1			1.6	2.1	2.1	2.6	3.3	4.0	4.0	4.7
STF-029SA1			1.8	2.2	2.2	2.7	3.4	4.1	4.1	4.8	5.5	6.3	7.8	8.0
STF-034SA1			2.7	3.0	3.0	3.3	4.0	4.8	4.8	5.6	6.5	7.8	9.0	10.7	12.0	12.0
STF-039SA1				3.4	3.4	4.0	5.0	6.1	6.1	7.1	8.2	9.3	10.4	11.5	12.8	14.0	15.3	16.6	17.0
STF-044SA1							6.0	8.3	8.3	9.8	11.3	12.8	14.3	16.0	17.3	18.8	20.3	21.8	23.5	24.8	27.8	30.0
STF-056SA1							10.7	11.9	11.9	13.4	14.9	16.3	17.8	18.7	20.8	22.2	23.7	25.2	27.0	32.0	41.9	52.0	56.3	60.0	60.0

*Check the this list as there may be limitations on the standard and maximum torque caused by the holding power of the coupling shaft section.

*The Max. limit-received torque is a torque value of the small diameter side (d1). However, only in the case that STF-019SA1's d1 or d2 is φ8mm does the clamp bolt size down, so the limiting value is 0.8N・m. Please keep this in mind.

[STF-019SA1 Standard bore diameter and Max. torque]

d1-d2	max. torque [N･m]	d1-d2	max. torque [N･m]	d1-d2	max. torque [N･m]	d1-d2	max. torque [N･m]	d1-d2	max. torque [N･m]	d1-d2	max. torque [N･m]	d1-d2	max. torque [N･m]
3B-3B	0.8	3B-4B	0.8	3B-5B	0.8	3B-6B	0.8	3B-6.35B	0.8	3B-7B	0.8	3B-8B	0.8
		4B-4B	1.2	4B-5B	1.2	4B-6B	1.2	4B-6.35B	1.2	4B-7B	1.2	4B-8B	0.8
				5B-5B	1.6	5B-6B	1.6	5B-6.35B	1.6	5B-7B	1.6	5B-8B	0.8
						6B-6B	1.9	6B-6.35B	1.9	6B-7B	1.9	6B-8B	0.8
								6.35B-6.35B	1.9	6.35B-7B	1.9	6.35B-8B	0.8
										7B-7B	2.3	7B-8B	0.8
												8B-8B	0.8

Download 3D CAD

STF-013SA1	(Shaft bore diameter[d1]:3~5 Shaft bore diameter[d2]:3~5)
STF-016SA1	(Shaft bore diameter[d1]:3~6 Shaft bore diameter[d2]:3~6)
STF-019SA1	(Shaft bore diameter[d1]:3~8 Shaft bore diameter[d2]:3~8)
STF-024SA1	(Shaft bore diameter[d1]:5~10 Shaft bore diameter[d2]:5~10)
STF-029SA1	(Shaft bore diameter[d1]:5~14 Shaft bore diameter[d2]:5~14)
STF-034SA1	(Shaft bore diameter[d1]:5~16 Shaft bore diameter[d2]:5~16)
STF-039SA1	(Shaft bore diameter[d1]:6~19 Shaft bore diameter[d2]:6~19)
STF-044SA1	(Shaft bore diameter[d1]:8~24 Shaft bore diameter[d2]:8~24)