What this motor is, and where it bolts in
The Siemens 1FK7042-2AK71-3SB0 is a SIMOTICS S 1FK7 synchronous servo motor rated 0.94 kW at a 600 VDC link, with a 3 Nm static torque figure (100 K) and a rated speed of 6000 rpm — a compact, high-dynamics servo sized for packaging, small-format converting, and feeder/indexing stations where a holding brake is required for vertical or overhung loads. Built on flange 1, IMB 5 design (also accepted in IM V1 and IM V3 mounting orientations), naturally cooled, with cable outlet on the non-drive end and an IP64 seal class — meaning the housing resists dust ingress and splashed water, but is not rated for washdown; keep it out of wet zones on food, beverage, and pharmaceutical lines. Feedback is a multi-pole resolver (resolver P = 3), the rugged, low-resolution feedback choice that pairs naturally with Siemens SINAMICS S120 drive commissioning and tolerates the vibration and thermal cycles typical of packaging and material-handling machinery.
Why the holding brake and tolerance N matter at the panel
Shaft tolerance class N gives the standard running clearance — compatible with standard couplings and shrink-disc mounts in the 1FK7 family; if the driven machine expects a tighter balance grade (e.g. direct-coupled high-speed spindles) the standard keyway and tolerance are usually sufficient for 6000 rpm operation.
Lifecycle posture — last-time-buy window in view
For a procurement planner, an eol_hot rating means the BOM line needs a freeze date in mind: stock that exists in the authorised and independent channel is the supply going forward, and any new design-ins should plan for a replacement servo (typically the 1FK2 successor family for new builds, or a like-for-like 1FK7 unit pulled from traceable surplus) rather than a fresh factory order.