High Precision Linear Shafts-One End Tapped / One End Tapped with Wrench Flats
Caution
Product Description
[Features] Have a high accuracy in perpendicularity of shaft ends (0.03) and thus, are suitable for performing parts assembly that requires high accuracy.
High-Precision Linear Shafts, One End Tapped, with or without Wrench Flats
High-precision linear shafts, one end tapped, with or without wrench flats. Type, shaft diameter D, overall length L and coarse thread size M are set; wrench-flat versions also set the SC position and the W and ℓ1 dimensions.
Choose the type according to the required diameter tolerance, material, surface treatment, and wrench-flat configuration. This separates the fit-related choices from the end-thread and installation dimensions that define the selected shaft.
Material, surface treatment and hardness
- Surface roughness of part D differs between plated and unplated items.
- Tolerance of dimension L conforms to JIS B 0405 m class.
| Type | Material | Hardness | Surface treatment | ||
|---|---|---|---|---|---|
| Without wrench flats | With wrench flats | D tolerance | |||
| VFJT | VFJC | g6 | SUJ2 equivalent | Induction hardened (effective hardened depth: see table) SUJ2 equivalent 58HRC min. SUS440C or 13Cr stainless steel 56HRC min. | - |
| VSFJT | VSFJC | SUS440C or 13Cr stainless steel | |||
| VPFJT | VPFJC | SUJ2 equivalent | Hard chrome plating Plating hardness HV750 min. Plating thickness 5 μm min. | ||
| VPSFJT | VPSFJC | SUS440C or 13Cr stainless steel | |||
| VRJT | VRJC | SUJ2 equivalent | Low-temperature black chrome plating | ||
| VPSFJTG | VPSFJCG | f8 | SUS304 | - | Hard chrome plating Plating hardness HV750 min. Plating thickness 10 μm min. |
When D ≤ 5, the whole part may be hardened.
- Hard chrome plated items are machined after plating, so machined areas are not plated.
Part numbers and dimensions
Ordering example
| Type | - | L | - | M | - | SC |
|---|---|---|---|---|---|---|
| VFJT20 | - | 100 | - | M8 | ||
| VFJC20 | - | 100 | - | M8 | - | SC10 |
| D tolerance | ||
|---|---|---|
| D | g6 | f8 |
| 4 | -0.004 -0.012 | - |
| 5 | ||
| 6 | -0.010 -0.028 | |
| 8 | -0.005 -0.014 | -0.013 -0.035 |
| 10 | ||
| 12 | -0.006 -0.017 | -0.016 -0.043 |
| 13 | ||
| 15 | ||
| 16 | ||
| 18 | ||
| 20 | -0.007 -0.020 | -0.020 -0.053 |
| 25 | ||
| 30 | ||
| Type | L 1 mm increments | M (coarse) Selection | Wrench flat dimensions | C | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Type | D | SC | W | ℓ1 | ||||||||||||||
| (Without wrench flats) D tolerance g6 (D4–30) VFJT VSFJT VPFJT VPSFJT VRJT D tolerance f8 (D6–30) VPSFJTG | (With wrench flats) D tolerance g6 (D6–30) VFJC VSFJC VPFJC VPSFJC VRJC D tolerance f8 (D6–30) VPSFJCG | 4 | 25–200 | 2 | - | - | - | 0.2 or less | ||||||||||
| 5 | 25–300 | 2.6 | 3 | |||||||||||||||
| 6 | 20–350 | 3 | SC: 1 mm increments SC+ℓ1 ≤ L SC ≥ 0 | 5 | 8 | 0.5 or less | ||||||||||||
| 8 | 20–500 | 3 | 4 | 5 | 7 | |||||||||||||
| 10 | 20–500 | 3 | 4 | 5 | 6 | 8 | ||||||||||||
| 12 | 20–500 | 4 | 5 | 6 | 8 | 10 | 10 | |||||||||||
| 13 | 20–500 | 4 | 5 | 6 | 8 | 11 | ||||||||||||
| 15 | 20–500 | 4 | 5 | 6 | 8 | 10 | 13 | |||||||||||
| 16 | 20–500 | 4 | 5 | 6 | 8 | 10 | 14 | |||||||||||
| 18 | 20–500 | 4 | 5 | 6 | 8 | 10 | 12 | 16 | ||||||||||
| 20 | 25–500 | 4 | 5 | 6 | 8 | 10 | 12 | 17 | 1.0 or less | |||||||||
| 25 | 25–500 | 4 | 5 | 6 | 8 | 10 | 12 | 16 | 22 | |||||||||
| 30 | 25–500 | 6 | 8 | 10 | 12 | 16 | 20 | 27 | 15 | |||||||||
Overall length L must satisfy M×2 ≤ L. When M×2.5+4 ≥ L, the tap drill hole goes through.
Alterations
Alterations are available. Refer to the alteration table for applicable codes, dimensional limits and conditions.
For details, please see the PDF catalog.
Technical reference
Straightness measurement
Support both shaft ends on V-blocks, rotate the shaft once and measure the dial gauge amplitude at any point.
Straightness is 1/2 of the measured amplitude.
Roundness M: shafts with O.D. g6 (hardened)
| D | Roundness M | |
|---|---|---|
| Over | Up to | |
| 3 | 13 | 0.004 |
| 13 | 20 | 0.005 |
| 20 | 30 | 0.006 |
Roundness M: shafts with O.D. f8 (not hardened)
| D | Roundness M | |
|---|---|---|
| Over | Up to | |
| 6 | 10 | 0.011 |
| 10 | 18 | 0.014 |
| 18 | 30 | 0.017 |
Straightness K: shafts with O.D. g6 (hardened)
| D | L | Straightness K |
|---|---|---|
| 4 | No condition | (L/100)×0.05 or less |
| 5 | No condition | (L/100)×0.03 or less |
| 6–30 | L≤100 | 0.01 or less |
| L>100 | (L/100)×0.01 or less |
Straightness K: shafts with O.D. f8 (not hardened)
| L | Straightness K |
|---|---|
| L≤100 | 0.025 or less |
| L>100 | (L/100)×0.025 or less |
L dimension tolerance: shafts with O.D. g6 (hardened)
| L | L dimension | |
|---|---|---|
| Over | Up to | Tolerance |
| 19 | 30 | ±0.2 |
| 30 | 120 | ±0.3 |
| 120 | 400 | ±0.5 |
| 400 | 500 | ±0.8 |
L dimension tolerance: shafts with O.D. f8 (not hardened)
| L | L dimension | |
|---|---|---|
| Over | Up to | Tolerance |
| 14 | 30 | ±0.2 |
| 30 | 120 | ±0.3 |
| 120 | 400 | ±0.5 |
| 400 | 500 | ±0.8 |
Unit: mm
Hardness reduction at machined areas
- Machining is done after hardening, but annealing for machining may reduce hardness.
- *Hardness after reduction: approx. 10–40HRC
Hardness may be reduced at wrench flats and flats (approx. 10 mm from the machined area).
Hardness reduction at female threads: the conditions depend on material and selection.
SUS440C or 13Cr stainless steel: hardness is reduced at the female thread.
SUJ2 equivalent: under the conditions below, hardness is reduced at the female thread.
- When M ≥ D/2
• RC threads
• 2-hole female thread type
Effective hardened depth: depends on outer dimensions and material.
| O.D. D | Effective hardened depth | |
|---|---|---|
| SUJ2 equivalent | SUS440C / 13Cr stainless steel | |
| 4 | 0.5 or more | 0.5 or more |
| 5 | ||
| 6–10 | ||
| 12, 13 | 0.7 or more | |
| 15–20 | 0.7 or more | |
| 25, 30 | 1.0 or more | |
Hard chrome plated items are machined after plating, so machined areas are not plated.
Shafts vs. rotary shafts
- Specification comparison: linear shafts and rotary shafts
Basic specifications
| Specifications | Shaft | Rotary shaft | ||
|---|---|---|---|---|
| Material | SUJ2 equivalent SUS440C or 13Cr stainless steel | S45C equivalent SUS304 | S45C equivalent SUS304 | SCM435 |
| Hardening | Induction hardening | - | - | Hardness 30–35HRC |
| O.D. tolerance | g6/h5 | f8 | g6/h9/h7 | g6 |
| Surface treatment | No plating Hard chrome plating Low-temperature black chrome plating Electroless nickel plating (full-length treatment type) | Hard chrome plating | No plating Black oxide Electroless nickel plating | Black oxide Electroless nickel plating |
- *With hard chrome plating, no plating remains on machined areas.
Overview and technical notes
Hardness may be reduced by annealing at wrench flats and machined shaft ends (effective thread length + approx. 10 mm).
The shaft end face may have a center hole.
Application examples
- The precision type needs no stepped machining like Ⓐ, which helps assembly.