Métafram sintered bearings
Métafram sintered bearings are porous, lubricant-containing plain bearings made of bronze BP 25 or iron FP 20. The rotating shaft removes lubricating oil from the pores by means of a suction effect. After the shaft has stopped and cooled down, this is then sucked back into the bushing by way of capillary action. As the oil cannot be lost through circulation during rotary movements, Métafram bearings are self-lubricating.
Mechanical and physical properties
Métafram BP 25 FP 20
Standard comparison similar SINT A50 A10
Impregnation oil Shell Turbo T 100 (ISO VG 100) Shell Turbo T 100 (ISO VG 100)
Specific gravity [kg/dm3] ≥ 6,2 ≥ 5,6
Open porosity [%] ≥ 23 ≥ 20
Admissible static load [N/mm2] ≤ 20 ≤ 45
Admissible dynamic load [N/mm2] ≤ 10 ≤ 22
Admissible sliding speed [m/s] ≤ 6 ≤ 4
PV value under hydrodynamic lubricating conditions (vmin = 0,5 m/s) [N/mm2 x m/s] 1,8 1,8
Admissible temperature range [°C] -5/+90 -5/+90
Table of contents
> Mechanical and physical properties
> Machining
> Re-impregnation
> Special impregnation
> Special sizes
> Special alloys
> Typical applications
> Cylindrical bearings BP 25 und FP 20
> Flanged bearings BP 25 und FP 20
> Fitting mandrel
> Bearings before fitting
> Housing bore made of steel
> Bearings after fitting
> Shaft
> Links
Machining
Métafram standard bearings are mass produced and very reasonably priced. It is therefore advantageous to provide the standardised sizes as early as the design stage. However, if special dimensions are required, these can be produced by machining. The running surfaces must not be ground or rubbed, as this will press shut the oil-carrying pores. Sintered metals can be processed with carbide (K10/K20). Cutting speed 140-200 m/min. Oil is lost during processing, which can be compensated by subsequent re-impregnation. On request, we will be pleased to send you the detailed information sheet on the processing of sintered parts.
Re-impregnation
After machining, the bearings are heated to 80°C in an oil bath for one hour and then allowed to cool. The same oil that was used for the original impregnation must be used for re-impregnation.
Special impregnation
For the use of bushings outside the temperature range of -5°C to + 90°C we offer other lubricant impregnations as special production. Please ask us.
Special sizes
Dimensions that are outside the standard range can be manufactured according to your drawing. Smaller quantities are machined, as described above. For larger production volumes, suitable tools are produced and the unit prices are then similar to those for the standard sizes.
Special alloys
Métafram offers special alloys for exceptional stresses, especially for very high loads. We will be pleased to quote for these.
Typical applications
Métafram sintered bearings are used in the following sectors of the machinery and consumer goods industry: Machine tools, textile machines, packaging machines, printing machines, agricultural machines, vehicles, ventilation and air conditioning systems, household appliances, electric hand tools, electric motors, office machines, toys, medical devices, optical devices, reduction gears, etc.
Cylindrical bearings BP 25 und FP 20
d1 : ≤ 50 mm: F7 > 50 mm: F8
d2 : ≤ 50 mm: s7 > 50 mm: s8
b1 : ≤ 10 mm: ±0,1 mm > 10 mm: ±1%
f : Edge break (0,1-0,2) x s; min. 0,2
Concentricity: Maximum deviation of the dial gauge values when the bushing is fully turned on a mandrel.
Inside-Ø ≤ 25 mm: Tolerance: 50 µm
Inside-Ø > 25 mm: Tolerance: 70 µm
Flanged bearings BP 25 und FP 20
d1 : F8
d2 : s8
d3 : js13
b1 : ≤ 10 mm: ±0,1 mm > 10 mm: ±1%
b2 : js14
f : Edge break (0,1-0,2) x b2; min. 0,2
rmax : 0,3 x b2
Concentricity: Maximum deviation of the dial gauge values when the bushing is fully turned on a mandrel.
Inside-Ø ≤ 25 mm: Tolerance: 60 µm
Inside-Ø > 25 mm: Tolerance: 80 µm
Fitting mandrel
Ø-Tolerance dP: m6
The sintered bushings are inserted into the locating hole with the press. The recommended mandrel tolerance is important to ensure:
- a perfect press fit, and
- the desired end bore tolerance.
Bearings before fitting
Please note the information on page 20.
Ø d1 Cylindrical bearing: F7/F8
Ø d1 Flanged bearing: F8
Ø d2 Cylindrical bearing: s7/s8
Ø d2 Flanged bearing: s8
Housing bore made of steel
Ø-Tolerance dB H7
A locating hole with the tolerance H7 and the bushing tolerances provides the right overlap for an adequate press fit and the correct end bore tolerance. If the locating hole is not made of solid steel, attempts should be made to determine the bore tolerances. We are happy to help.
Bearings after fitting
Bore tolerances:
Cylindrical bearing dE:
with inside-Ø < 50 mm H7
with inside-Ø ≥ 50 mm H8
Flanged bearing dE: H8
Shaft
Tolerance dW f7
Shaft materials:
for BP 25: Steel Rm ≥ 600 N/mm2
for FP 20: Steel Rm ≥ 800 N/mm2
The shaft surface should be ground if possible. The finer the surface, the longer the service life. When using stainless steel shafts, we recommend rolling or hard chrome plating.
We will be more than pleased to advise you.
Subject to technical modifications; no responsibility is accepted for the accuracy of this information.
