^{Pins and Bushings for Excavators, Backhoe Loaders and Heavy Equipment}

Mahmut Usta Yedek Parca supplies pins, bushings and pin kits for construction and mining equipment. These are the joints that carry every load the machine handles: boom, arm, bucket, linkage, quick coupler, swing frame and cylinder mounts. Parts are supplied individually and as kits, and items that are unavailable or out of production are machined to order.

^{Bucket Pins and Ordering by Size}

Bucket pins are ordered by size more often than by part number, because the number stamped on a pin is the first thing to wear off. We stock bucket, boom and linkage pins in standard and repair diameters, including the smaller sizes used on mini excavators, which are the most frequently requested group.

To order by size, four measurements are enough: outside diameter, overall length, position and width of the grease grooves, and whether the pin has a lock hole, a flat or a retaining plate. Measure the diameter at the very end of the pin, on the section that never ran inside the bushing, because the worn area gives a false reading.

^{Pins and Bushings for Caterpillar, Komatsu and JCB}

Bucket pins and bushings for Caterpillar, Komatsu, Volvo, JCB, Hitachi, Case, New Holland, Hidromek, Terex, Hyundai and John Deere machines, covering excavators, backhoe loaders, wheel loaders, mini excavators and skid steers. Backhoe loaders are the heaviest users of these parts. Loaded at the front by the bucket and at the rear by the boom, they run more working pin joints than any other machine of their size, and the front and rear groups wear at different rates.

^{Bronze and Steel Bushings}

Bushings are supplied in case hardened steel and in bronze, depending on the joint and the lubrication it receives. Bronze suits joints that are greased regularly and run at low speed under high load. Hardened steel suits joints exposed to shock and abrasive contamination, where a softer bushing would deform. Fitting the wrong material is a common cause of repeat failures: bronze in a dry, dirty joint wears in a matter of weeks.

^{Repair Sizes and Oversize Bushings}

When a pin wears, the bore wears with it. An oval bore will not hold a standard pin, and fitting a new pin into a worn boss produces the same failure within a short time. In that case the bore is line bored and an oversize bushing is fitted. We supply oversize bushings and repair diameter pins, and machine them to the actual bored dimension when a standard repair size does not fit. Correct clearance in a pin and bushing pair is measured in tenths of a millimetre and depends on joint diameter. Play that can be felt by hand means the clearance has already grown several times over, and the joint is now wearing the housing rather than the bushing.

^{Custom Machined Pins and Bushings}

We machine pins and bushings to drawing, to sample or to measurements taken from the worn part. This covers machines out of production, rare models, and cases where the original part has an unacceptable lead time. Pins are produced from case hardening and quenched and tempered steels with heat treatment after machining. Case depth matters as much as surface hardness: a pin with a hard but shallow case collapses under shock loading and the surface begins to flake within a few hundred hours.

^{Replace as a Set}

Pins and bushings bed into each other in service. A new pin in a worn bushing goes oval within a few shifts, and a new bushing on a worn pin wears just as fast. They are replaced as a matched set. When changing boom bushings, check the grease passages and fittings at the same time. Accelerated wear is more often caused by grease not reaching the surface than by load.

^Fasteners

Also available: track shoe bolts and nuts, track pad bolts, cutting edge and tooth bolts, plow bolts, rim bolts and nuts, studs, washers, retaining rings and cotter pins.

^{Part Identification}

Parts can be matched by OEM part number, by machine model and serial number, or by measurements taken from the old part. Cross referencing between original numbers and equivalents is provided free of charge.

^Applications

Pins and bushings are used in excavators, backhoe loaders, wheel and track loaders, mini excavators, skid steer loaders, dozers, motor graders, articulated and off-road dump trucks, hydraulic mining excavators, underground mining machines and forestry equipment.