Spindle repairs and reconditioning with quick TAT, all brands, documented QC
WhatsApp
Precision Machinekraft Pvt Ltd Logo
Menu

Technical Information & Designation

Understanding the model numbering system and technical specifications of PMK ball screws is essential for selecting the right component for your machinery.

1. Model Number Configuration

The PMK designation system combines several technical parameters into a single string. Use the guide below to decode your product name.

PSFT
Nut Type code
R
Direction of helix
025
Shaft Dia. (mm)
05
Lead (mm)
B2
No. of Turns
D
Flange type
G
Process code
C5
Accuracy Grade
1000
Length of shaft
P0
Axial Clearance And preload code

Nut Type Code

  • Prefix: PS (e.g. PSFI, PSFT)
  • S / D: Single Nut / Double Nut
  • F / C: With Flange / Without Flange
T T : T type nut
I : I type nut
D : D type nut
E : E type nut
K : K type nut
U : U DIN nut

Direction of Helix

  • R: Right Hand (Standard)
  • L: Left Hand

No. of Turn (Circuits) or Turn x Row

    Turn T : 1
    A : 1.5 (or 1.7)
    B : 2.5
    C : 3.5

    ex : (B2=2.5x2)

    Flange Type

    • N: Cylindrical
    • PS: One side Cut
    • D: Both sides Cut

    Process code

    G: Ground
    R: Rolled

    Accuracy grade code

    C0 C1 C2 C3 C5 C7 C10

    Axial clearance and preload code

    P0 P1 P2 P3 P4

    2. Technical Specifications

    Mean Travel Deviation (±E) and Travel Variation (e) (JIS B 1192) unit: µm

    Grade C0 C1 C2 C3 C5 C7 C10
    Travel Length
    (mm)    		 Over incl ±E e ±E e ±E e ±E e ±E e e300 e300
    Travel Length (mm) 100 3 3 3.5 5 5 7 8 8 18 18 ±50
    300mm    		 ±210
    300mm
    100 200 3.5 3 4.5 5 7 7 10 8 20 18
    200 315 4 3.5 6 5 8 7 12 8 23 18
    315 400 5 3.5 7 5 9 7 13 10 25 20
    400 500 6 4 8 5 10 7 15 10 27 20
    500 630 6 4 9 6 11 8 16 12 30 23
    630 800 7 5 10 7 13 9 18 13 35 25
    800 1000 8 6 11 8 15 10 21 15 40 27
    1000 1250 9 6 13 9 18 11 24 16 46 30
    1250 1600 11 7 15 10 21 13 29 18 54 35
    1600 2000 - - 18 11 25 15 35 21 65 40
    2000 2500 - - 22 13 30 18 41 24 77 46
    2500 3150 - - 26 15 36 21 50 29 93 54
    3150 4000 - - 30 18 44 25 60 35 115 65
    4000 5000 - - - - 52 30 72 41 140 77
    5000 6300 - - - - 65 36 90 50 170 93
    6300 8000 - - - - - - 110 60 210 115
    8000 10000 - - - - - - - - 260 140
    10000 12500 - - - - - - - - 320 170

    Variation per 300mm (e300) and Wobble Error (e2π) unit: µm

    Grade C0 C1 C2 C3 C5 C7 C10
    e300 3.55781850210
    e2π 2.54568--

    Combination of Accuracy Grade and Preload

    Grade P0 P1 P2 P3 P4
    Axial Play YesNoNoNoNo
    Preload NoNoLightMediumHeavy

    3. Accuracy & Preload Selection

    Guidelines for selecting Accuracy, Preload, Axial Play, Nut and Screw shaft.

    Accuracy Preload and Axial Play Nut Type Screw shaft Type
    C10 P0 (With Axial Play) Single Nut Rolled screw shaft
    C7 Rolled : P0 Ground : P1 Rolled : Single Nut Ground : According to PMK Catalogues Rolled or Ground
    C5 P1 or P2 (Standard) Ground : According to PMK Catalogues Ground screw shaft with
    lead error inspection certificate
    C3 P1 or P2 (Standard) or P3 Ground : According to PMK Catalogues Ground screw shaft with
    lead error inspection certificate

    Axial Play (P0) Clearance in the Axial Direction of the Rolled and Ground Ball Screw

    unit: mm
    Screw Shaft OD Rolled Ball Screw
    Clearance (max.)    		 Ground Ball Screw
    Clearance (max.)
    04-14 miniature 0.05 0.015
    15-40 middle size 0.08 0.025
    50-100 big size 0.12 0.05

    Spring Force of Light Preload (P2) unit: kg

    Model No. Single Nut Double Nut
    1605 0.1 ~ 0.3 0.3 ~ 0.6
    2005 0.1 ~ 0.3 0.3 ~ 0.6
    2505 0.2 ~ 0.5 0.3 ~ 0.6
    3205 0.2 ~ 0.5 0.5 ~ 0.8
    4005 0.2 ~ 0.5 0.5 ~ 0.8
    2510 0.2 ~ 0.5 0.5 ~ 0.8
    3210 0.3 ~ 0.6 0.5 ~ 0.8
    4010 0.3 ~ 0.6 0.5 ~ 0.8
    5010 0.3 ~ 0.6 0.8 ~ 1.2
    6310 0.6 ~ 1.0 0.8 ~ 1.2
    8010 0.6 ~ 1.0 0.8 ~ 1.2

    4. Cautions About Use of Ball Screws

    Lubrication

    Adequate lubrication must be provided when ball screw is used, insufficient lubrication will result in contact of metal, which in turn leads to increase of friction and friction loss, thus cause failure or shortening of service life.

    Lubricants applied to ball screws can be divided into 2 types, namely lubricating oil and consistent grease. In general speaking, in respect of maintenance, consistent grease will lead to increase of dynamic friction torque linearly along with increase of rotating speed, hence oil lubrication is deemed the better way when speed exceeds 3-5 m/min; however, don't forget the fact that there have been examples that using grease has been capable of achieving speed of 10 m/min, with respect to the equipment.

    Inspection of lubrication and interval of refill

    Method Interval Check Item
    Replenish or Change Interval
    Auto.
    Intermittent
    oil supply    		 Weekly Oil level,
    contamination
    Add at each check, as required depending on tank level
    Grease initially 2-3
    months    		 Contamination
    on entry of chip
    Replenish yearly or according to the inspection results
    Oil bath Daily Oil level
    To be determined according
    to consumption

    Contaminant Prevention

    Any foreign matter or water, if allowed to enter the ball screw, may increase friction and cause damage. For example, the entry of chips or cutting oil may be expected with machine tools depending on the work environment. Where entry of foreign matter is anticipated, use a bellows or telescopic cover as shown in Fig 5.1, to cover the screw shaft completely.

    Ball screw contaminant prevention diagram showing bellows and telescopic cover installation

    5. Ball Screw Selection Matrix

    Ground & Rolled Ball Screw Availability Matrix

    Dia. Lead (mm)
    1 2 2.5 2.54 3 4 5 5.08 6 8 10 12 15 16 20 24 25 32 40 50 64
    4
    6
    8
    9
    10
    12
    14
    15
    16
    19
    20
    25
    28
    32
    36
    38
    40
    45
    50
    63
    80
    100
    Both Ground & Rolled available
    Ground Ball Screw only

    Need the full selection procedure matrix and dimensional diagrams?

    Download Full PDF Catalogue (4.1MB)