Boeing · Electronic Components
ST5M1243-3121
Relay, Electromagnetic
Part NumberST5M1243-3121
ManufacturerBoeing
AvailabilityAvailable to order — request a quote
Specifications
NSN5945-01-212-5393 (NSN)
Federal Item NameRELAY,ELECTROMAGNETIC
Federal Supply Class5945 — Relays and Solenoids
Overall Width1.050 INCHES MAXIMUM
Main Contact Load Current Rating A4.0 AMPERES AC AND 4.0 AMPERES DC MOTOR LOAD
Storage TypeGENERAL PURPOSE WAREHOUSE
Winding Quantity1
Cubic Measure4.185 CUBIC INCHES
Duty TypeCONTINUOUS
Arc Quenching MethodAIR
Mounting Facility Type And Quantit1 PLUG-IN TERMINAL(S) SINGLE MOUNTING FACILITY
Nonpile Up Main Contact Arrangemen2 POLE, DOUBLE THROW, ONE POSITION MOMENTARY
Fragility FactorMODERATELY RUGGED
Coil Quantity1
Vendor Part NumbersCTD210-3121
RH Electronics, Inc. — independent stocking distributor since 1982.
Every shipment inspected on receipt · ISO 9001:2015 · ANSI/ESD S20.20 · ERAI member since 1998 · GIDEP participant
Every shipment inspected on receipt · ISO 9001:2015 · ANSI/ESD S20.20 · ERAI member since 1998 · GIDEP participant
Frequently asked
Is ST5M1243-3121 available?
We can source ST5M1243-3121 even if it isn't in our active stock list. As an independent distributor we reach inventory outside the franchise channel — including hard-to-find and obsolete parts. Send us a quote request.
Is ST5M1243-3121 by Boeing obsolete or end-of-life?
We specialize in obsolete, end-of-life, and discontinued components. If ST5M1243-3121 has been discontinued, we can often source remaining stock or qualified alternates. Contact us with your quantity and target date.
How does RH Electronics verify parts like ST5M1243-3121?
Every incoming shipment is inspected under our ISO 9001:2015 quality system — documentation, markings, and construction checked against known-good references. For deeper analysis, we direct work through accredited independent labs. We've been an ERAI member since 1998 and a GIDEP participant.
Can you find a cross-reference or alternate for ST5M1243-3121?
Yes. Our team reads part numbers the way they were designed — decoding family, speed, temperature grade, package, and reliability level — to identify acceptable alternates when the exact part isn't available. Submit a quote request and we'll advise.