Installation Procedure
Complete guidance for storage, handling, preparation, fitting, lubrication, pre-load setting, and running-in of Gamet Super Precision Tapered Roller Bearings.
After inspection, all Gamet bearings are treated with a corrosion preventative oil (except pre-greased bearings). Initial packaging consists of heavy-gauge PVC bags that are heat-sealed and then placed in protective boxes.
- Bearings can be stored for long periods if packaging is undamaged
- Storage area must be dry and not subject to extremes of temperature
- Do not open packaging until immediately before fitting
- Store horizontally — do not stack heavy items on bearing boxes
- Avoid storage near equipment that generates vibration
Gamet super precision bearings are manufactured to extremely close tolerances. Careless handling can cause damage that is not visible to the naked eye but severely compromises bearing performance.
- Handle with clean, dry hands or lint-free gloves
- Never expose bearings to grit, dust, or metal particles
- Inspect races and rollers visually — any pitting, scoring, or flaking requires rejection
- Verify part number matches the drawing before fitting
- For GE/HE spacer types: verify the preload code matches the machine specification
Flush with clean solvent (white spirit or equivalent). Ensure complete removal before applying operating lubricant.
Inspect rollers and races under good lighting. Look for rust spots, scores, or surface irregularities. Measure bore and OD if in doubt.
Single Row Plain (cone + cup) are sold as matched sets. Never mix cone and cup from different matching pairs unless specified.
The performance of a super precision bearing is directly dependent on the quality of fit of the housing bore and shaft diameter.
- Shaft tolerance: Typically k5 or m5 for interference fits (inner ring rotating load)
- Housing tolerance: Typically H6/K6 to allow removal of the cup
- Cleanness is paramount — remove all burrs, swarf and grinding particles
- Measure housing bore and shaft journal at multiple points to check roundness and straightness
- Apply a thin film of clean oil to the housing bore and shaft journal before fitting
The following procedure covers the assembly of Gamet H & P Type bearings to a typical lathe spindle, as specified by Gamet's official guidelines.
Adjust front cap to ensure front bearing cup is securely seated. Adjust and lock rear spacer (If fitted or required). Heat both bearing cones to a maximum of 80⁰ - 100⁰ C, using an induction heater.
When heat is achieved, push firmly onto the spindle to ensure they are seated correctly against the abutting shoulder. Ensure rear bearing cup is perfectly clean, push lightly by hand into rear housing. Fit rear cap adjusting lightly to seat bearings.
Stand spindle vertically and mount dial indicator. Rotate spindle several times and obtain a steady zero-reading on the dial gauge. Back-off the front measuring face until approximately 3-4 mm clearance. Re-set dial gauge to zero. Note: Do not rotate spindle after backing-off the measuring face.
Reverse Spindle in fixture. Using a suitable weight (equivalent to radial load + radial load/2), push outer race progressively to remove any existing slop between bearing rollers and tracks.
Rotate spindle several times to allow rollers to re-seat themselves, to give an accurate indicated value. Continue measuring the displacement over all 3 struts, note mean, repeat until value is identical to within 1-2 microns. Record identical value.
Apply 2-3 drops of oil to each bearing roller assembly. Re-grease bearings thoroughly. Fit spindle into headstock, ensure rear bearing cup is securely clamped to housing face, via the two outer caps.
Note: Ensure spindle rotates freely by hand, prior to attempting final adjustment. Measure required gap to determine required pack-size.
Measure pack and carefully grind to correct size. Remove spacer and lock-nut. Fit correct-size pack, replace spacer and securely lock by tightening lock-nut as per instructions. Ensure spindle rotates freely by hand and measure axial run-out if requested/required.
Correct lubrication is the most critical factor in achieving optimum bearing life. Gamet bearings are designed for either oil or grease lubrication depending on application requirements.
Grease Lubrication
- Use NLGI Grade 2 high quality lithium-based grease
- Fill approximately 30–40% of free space in the bearing and housing
- Do not over-grease — excess causes churning, heat, and premature failure
- Re-grease at manufacturer recommended intervals (typically every 2,000–4,000 hours depending on speed and load)
Oil Lubrication (recommended for spindle applications)
- Circulating oil system preferred for continuous duty machine tool spindles
- ISO VG 32 or VG 46 mineral or synthetic spindle oil depending on speed
- Oil temperature should not exceed 70°C at the bearing; check with thermocouples if possible
- Oil flow must be adequate to carry away heat — consult machine designer for flow rates
- Filter oil to at least 10 microns — contamination is the primary cause of premature bearing failure
Pre-load is the controlled elimination of internal clearance in the bearing pair. It increases stiffness, reduces runout, and extends bearing life when set correctly. Incorrect pre-load — especially excessive pre-load — greatly reduces bearing life.
Understanding the Preload Code (HE/GE Type)
For bearings with the E suffix (spacer variants — HE and GE types), the preload is determined by the internal spacer. The numeric code after "E" denotes the preload offset:
| Part Suffix | Preload Level | Space Offset | Typical Use |
|---|---|---|---|
HE0 / GE0 |
Zero / Nominal | ±0 µm | Standard general purpose |
HE+10 / GE+10 |
Light | +10 µm | Higher speed, lower load |
HE+20 / GE+20 |
Medium | +20 µm | Medium speed/load |
HE+30 / GE+30 |
Heavy | +30 µm | Heavy cutting, low speed |
HE+40 / GE+40 |
Extra Heavy | +40 µm | Very heavy duty |
HE-10 / GE-10 |
Reduced | -10 µm | Very high speed, minimal load |
Axial Adjustment (non-spacer types)
- Use a calibrated torque wrench or dial gauge to measure running torque / axial deflection
- Tighten the locknut progressively until the specified preload deflection is reached
- Verify with a dial indicator: rotate the shaft, measure axial float — target is zero or specified value
- Check that the shaft rotates freely by hand — binding indicates over-preload
A controlled running-in period allows oil films to fully establish, surface micro-contacts to smooth, and temperature to stabilise.
Monitor temperature every 5 minutes. Temperature should stabilise. If it continues rising sharply, stop and investigate over-lubrication or over-preload.
Check for abnormal noise. A smooth hum is normal. Grinding, squealing, or irregular noise indicates a problem.
Begin light cutting passes or equivalent load. Check vibration levels with a vibration analyser if available.
Bearing temperature should stabilise at 20–40°C above ambient. Steady-state within ±5°C indicates a well-fitted bearing.
- Inspect at every major machine service interval (typically 4,000–8,000 hours)
- Check for: increased vibration, rising operating temperature, unusual noise, reduced spindle accuracy
- When replacing bearings, always replace the complete matched set (cone + cup, or both cones for double-row)
- Clean housing thoroughly before fitting new bearings
- Check housing bore and shaft for wear — replace if dimensions are outside tolerance
- Record bearing replacement date and part number in the machine maintenance log