MRC7116KRDTDBAngular Contact Ball Bearing Set – Straight Bore, 80 mm ID, 125 mm OD, 22 mm Width Each, 15° Contact Angle, ABEC 7, Tandem Back-to-Back

Product Description

What this part is

MRC 7116KRDTDB angular contact ball bearing set. Bore: 80 mm. Outside diameter: 125 mm. Width: 22 mm per bearing. Series: 7100K, extra light. Contact angle: 15°. Precision Class: ABEC 7. Straight bore, chrome bearing steel. Country of origin: United States.

Decoding the designation

Base number 7116, written on the carton as 7116KRDTDB, 7116 KR DT DB and 7116 KRDTDB. R: 15° contact angle, counterbored outer ring. DT: tandem. DB: back-to-back. DTDB: a tandem group mounted back-to-back against a second group, ground and matched as one stack.

What these specs mean in practice

A 15° contact angle gives high speed capability and low friction, with moderate thrust capacity per bearing. The counterbored outer ring accepts a fuller ball complement, which raises radial capacity. Tandem bearings share thrust in one direction, so axial capacity rises roughly in proportion to the number of bearings facing that way. The back-to-back joint carries thrust the other direction and gives the stack high angular rigidity, which holds shaft deflection and tilt to a minimum. ABEC 7 gives close running accuracy, low radial and axial runout and low running vibration — the grade used on machine tool spindles.

Quantity and configuration

One matched DTDB stack, supplied as a set. Each bearing measures 80 x 125 x 22 mm. The bearings are ground together and stay together as a unit.

Fitting notes

Bearings from a matched stack are mounted in the marked relationship — the stamped outer ring faces are adjacent at the back-to-back joint, and within each tandem group the stamped face of one bearing sits against the unstamped face of the next. Shaft and housing fits are kept light on a controlled-face set, since internal clearance changes the flushness of the ring faces. A back-to-back stack is clamped axially on the shaft and left free to float in the housing so the assembly can grow with temperature.

Interchange guidance

The 80 x 125 x 22 mm envelope corresponds to the ISO 7016 section. A same-envelope bearing at a 25° or 40° contact angle is a related size, not a substitute, and neither is a bearing of a lower precision class. Searchable forms: 7116KRDTDB, 7116 KRDTDB, 7116-KR-DTDB, 7116 KR DT DB, 7116KR DTDB, 7116KR.