Balls HK30 bushing black

Ball knobs HK30 bushing are handle balls in nylon PA6 with a threaded brass bushing, made for levers that are fitted and removed often. The metal thread is the whole idea behind the product; where a thread straight in plastic eventually wears from repeated tightening, the brass takes the ball being screwed on and off year after year without the joint going loose.

The shape is clearly different from a classic round lever ball. The diameter is 39 mm and the height a full 53 mm, so the ball is elongated rather than round; that gives the hand more bearing surface in the pulling direction and a steadier grip on levers that are moved with force. The hole is 47 mm deep according to the data sheet, which means the end of the lever can reach far into the ball and give the joint good guidance. The thread comes in M8 and M10, and you pick the size as a variant on the product page.

PA6 and brass are a proven combination in grips. The nylon provides toughness and impact resistance: the ball does not crack from a drop on the floor or a knock from a pallet, and the matte black surface gives a hold even for oily gloves. The brass provides the precision and service life of the thread, and it does not corrode in a normal workshop.

Where is the metal thread needed? Everywhere the ball does not sit still for the whole life of the machine. Levers that are taken apart for cleaning in food production, control levers on equipment that is stripped down for transport between work sites, rental machines where the handles are replaced as they wear, and school workshops or test rigs where the same lever is readjusted over and over. In seasonal storage too, where levers come off before transport or washing, the brass thread does the job year after year. Balls with a plastic thread are cheaper, but only for as long as they do not have to be replaced.

The shape of the grip makes the ball a good choice on vertical and angled levers. A round ball is mostly gripped from above; an elongated ball like this one lies in the whole hand instead, rather like a gear lever grip, and takes the load off the fingers when the lever is moved against resistance. On control levers for conveyors, gates and agricultural implements that is a noticeable difference over a long shift. The shape works just as well on horizontal levers of course.

The well known moisture uptake of nylon has no practical significance here; a grip has no tolerance critical dimensions, and the brass thread is not affected at all. What you do get as a bonus is the thermal sluggishness of the material: the ball never feels ice cold the way a metal ball does in an unheated hall, and never burning hot next to a warm machine part. Small details, but they matter to whoever holds the lever all day.

Assembly is straightforward: screw the ball onto the threaded end of the lever until it stops and tighten by hand. The brass thread takes tool tightening better than a plastic thread, but the need rarely comes up; if the joint has to be secured against vibration, thread locking fluid or a low lock nut under the ball is enough. Check that the thread length of the lever fits in the 47 mm deep hole, which it nearly always does.

The balls are supplied in packs of 250 pieces, a volume that suits OEM assembly and central maintenance stores. If you need a smaller or round ball instead, HK35 in bakelite is in the range with diameters from 16 to 50 mm and threads from M4 to M16.

Do you need technical documentation before you decide? Get in touch and we will send the data sheet.