Sheet in PTFE BR60 1200x1200 mm natural

PTFE BR60 in sheet is a PTFE compound with about 60 percent bronze powder. That is the highest common bronze content in PTFE blends and takes the material as far as it goes toward maximum wear resistance and dimensional stability without losing the chemical character of the fluoroplastic. The sheet format suits large machined parts, wear surfaces against machine frames and prototype parts where you want room to mill complex geometry out of a single piece.

The high bronze content makes the material denser; density is around 4 g/cm3. Mechanically that means markedly less cold flow, higher compressive strength and better dimensional stability under load than both pure PTFE and BR compounds with less filler. The service temperature barely moves; the range stays between roughly minus 200 degrees and plus 260 degrees C continuously, and fire rating V0 applies. PTFE BR60 is therefore well chosen for large parts that have to sit under steady load for a long time, or where the dimensions are so large that even small creep would give unacceptable drift over time.

Friction is low, if not quite as low as pure PTFE, and the bronze leads friction heat away effectively. That raises the allowable PV level and makes the material suitable for combinations of higher pressure and moving load. At really high PV values, adding graphite can give further lubricating effect; BR55 GR is then an option. Chemically the base material is still PTFE and stands up to practically all industrial chemicals, solvents, acids and bases in normal use; the bronze can be affected by strong oxidizing acid, though, so with that kind of medium pure PTFE or PTFE GF is the better choice.

The sheet format is used for turned and milled parts such as slide plates, wear strips, guide rails, thrust bearings, piston rings in large sizes and sealing parts in pumps and compressors. Large sheets also suit prototype machining where the geometry drives the part out and you want plenty of material to work in. For industrial rebuilds where an old metal part is to be swapped for a plastic with the same or better wear profile, BR60 is often the choice, since the dimensions can in principle be kept and friction drops markedly.

Machining runs in the same spirit as other PTFE compounds. Carbide inserts with a positive rake angle give a fine surface, and light cooling with compressed air keeps heat build up in check. The high bronze content wears the cutting edges faster, so coated carbide or diamond is recommended for large runs. Drilling, milling and facing work without trouble; light polishing or scraping afterwards lifts the surface finish further and can be worth the trouble for sliding surfaces against a mating face. Ripping from larger sheets is done with a sharp blade and steady feed, preferably with a backing plate underneath to prevent breakout in the lower surface.

Thermal expansion is high, as with all PTFE based materials, so think through fits and fastening from the operating temperature. The material is not weldable or glueable with conventional methods, mechanical fastening is the norm. Through bolts with large washers, preferably combined with milled slots to allow movement, are a common solution for large sliding surfaces. On very long wear surfaces it is advisable to allow lengthwise movement at one of the fastening ends, so that thermal expansion does not build up stress in the material.

Sheets are stored flat and cool. Sheets in large dimensions can still move a little after a longer time on the shelf, so check the measurements before final machining. When ordering cut parts it usually pays to leave 1 to 2 millimeters of excess per machining direction, so that any warp can be trued up in the milling step. Sheets that are to be used for large slide plates against concrete or steel frames should be mounted with an even gap all around so they do not bind at the edges; this is extra important in outdoor applications where the temperature swing is large.

Stocked sheet dimensions in BR60 vary; for specific thicknesses or blanks cut to drawing, the simplest way is to send the dimensions straight over. Do you need to compare BR60 against BR40 or BR55 GR at your particular load level? Get in touch and we will go through PV values, chemical environment and tolerance requirements, and you get straight advice on which bronze content fits.

At 1200x1200 mm in natural the sheet is enough for several pressure bearing slide washers, and the high bronze content makes the material extra tough under load.