# How big are you quintet names made of brass

## Coefficient of friction

1. TE5910 | TC3 Motion Designer - Version 1.1
2. Common problems and questions
3. Coefficient of friction

In this chapter we give you basic information about the coefficient of friction.

 For each selected load case, a coefficient of friction (1) can be specified in the settings area.The values ​​to be entered depend on the application. Please check your load case in advance for possible friction fields and take the approximate values ​​from the tables below.

The coefficient of friction describes the ratio of the contact pressure between two bodies. A distinction is made between sliding and static friction. When designing a load case, the coefficient of friction between the selected materials must be taken into account.

In the table below you will find approximate values ​​which you can use for the load case design.
Please note that the friction is caused by several different factors such as:

• Material pairing
• surface
• lubrication
• temperature
• Humidity
• wear
• Normal force

is dependent and therefore no correct, but only guide values ​​can be given.

 Coefficient of friction with multiple bearings!Please note that several bearings can be used when designing a load case. This also changes the approximate value of yours Coefficient of friction. For detailed information, contact the Component manufacturer.

### Static friction

Static friction is a force that prevents bodies in contact from sliding. Static friction is the connection of bodies by means of a frictional connection. In the TC3 Motion Designer, static friction is assumed to be 0.

### Sliding friction

Sliding friction occurs on the contact surfaces between bodies that move relative to one another. With some material combinations, creep occurs so that the frictional force becomes speed-dependent. The sliding friction force is usually less than the static friction force with the same normal force. The coefficient of friction for sliding friction can be found in the table below based on various material pairings.

Material pairing

without lubrication

with lubrication

Static

Dynamic

Static

Dynamic

Aluminum on aluminum

1,2

1,4

0,3

---

Aluminum on mild steel

0,61

0,47

---

---

---

0,43

---

---

Bronze on cast iron

---

0,22

---

---

Bronze on steel

---

---

0,16

---

---

0,46

---

---

0,5

---

0,05

---

Chrome on chrome

0,41

---

0,34

---

Iron on iron

1

---

0,175

---

Solids on rubber

2,5

---

---

---

Mild steel on mild steel

0,74

0,57

---

0,1

Mild steel on brass

0,51

0,44

---

---

Mild steel on phosphor bronze

---

0,34

---

0,173

0,95

0,95

0,5

0,3

Mild steel on cast iron

---

0,23

0,183

0,133

Glass on nickel

0,78

0,56

---

---

Glass on metal

0,6

---

0,25

---

Glass on glass

0,95

0,4

0,35

0,1

Graphite on steel

0,1

---

0,1

---

Graphite on graphite

0,1

---

0,1

---

Cast iron on cast iron

1,1

0,15

---

0,07

Hard steel on hard steel

0,78

0,42

0,075

0,008

Hard steel on graphite

0,21

---

0,09

---

Hard steel on polystyrene

0,325

---

0,325

---

Hard steel on polyethylene

0,2

---

0,2

---

Magnesium on Magnesium

0,6

---

0,08

---

Brass on cast iron

---

0,3

---

---

Nickel on mild steel

---

0,64

---

0,178

Nickel on nickel

0,9

0,53

0,28

0,12

Nylon on nylon

0,2

---

---

---

Platinum on platinum

1,2

---

0,25

---

Plexiglass on Plexiglass

0,8

---

0,8

---

Plexiglass on steel

0,45

---

0,45

---

Polyethylene on steel

0,2

---

0,2

---

Polystyrene on steel

0,325

---

0,325

---

Polystyrene on polystyrene

0,5

---

0,5

---

Silver on silver

1,4

---

0,55

---

Steel on aluminum bronze

0,45

---

---

---

Steel on brass

0,35

--

0,19

---

Steel on cast iron

0,4

---

0,21

---

Steel on copper alloy

0,22

---

0,16

0,145

Steel on graphite

0,1

---

0,1

---

Steel on phosphor bronze

0,35

---

---

---

Teflon on steel

0,04

---

0,04

0,04

Teflon on Teflon

0,04

---

0,04

0,04

Zinc on cast iron

0,85

0,21

---

---

Zinc on zinc

0,6

---

0,04

---

Tin on cast iron

---

0,32

---

---

### Typical manufacturer specifications for load case-dependent coefficients of friction are:

Linear guide

Ball screw

Trapezoidal spindle

Plain bearing
Sintered bronze / steel

Plain bearing
Plastic / steel

µ1)

µ1)

η2)

µ1)

η2)

µ1)

η2)

µ1)

η2)

Conveyor belt

Rack and pinion

Rotary table

Spindle drive

0,001 – 0,003

0,003

0,96

0,20

0,32

Crank drive

0,001 – 0,003

0,04 – 0,12

0,10 – 0,20

Winder

1)Friction coefficient in µ and 2)Efficiency in η