MIL-SPEC · Electronic Components
NAS4121-291B
Heat Sink, Electrical
Part NumberNAS4121-291B
ManufacturerMIL-SPEC
AvailabilityAvailable to order — request a quote
Specifications
NSN5999-01-286-7295 (NSN)
Federal Item NameHEAT SINK,ELECTRICAL-ELECTRONIC
Federal Supply Class5999 — Miscellaneous Electrical Components
Overall Width1.810 INCHES NOMINAL
Overall Height0.750 INCHES NOMINAL
Material Document And ClassificatiQQ-A-250 FED SPEC SINGLE MATERIAL RESPONSE
Test Data Document81349-MIL-S-87111 SPECIFICATION (INCLUDES ENGINEERING TYPE BULLETINS, BROCHURES,ETC., THAT REFLECT SPECIFICATION TYPE DA
Overall Length1.810 INCHES NOMINAL
Unthreaded Mounting Hole Diameter0.190 INCHES NOMINAL ALL MOUNTING FACILITIES
Surface TreatmentANODIZE
Surface Treatment Document And ClaMIL-A-8625 MIL SPEC SINGLE TREATMENT RESPONSE
Mounting Facility Type And Quantit2 UNTHREADED HOLE(S) ALL MOUNTING FACILITIES
MaterialALUMINUM ALLOY
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 NAS4121-291B available?
We can source NAS4121-291B 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 NAS4121-291B by MIL-SPEC obsolete or end-of-life?
We specialize in obsolete, end-of-life, and discontinued components. If NAS4121-291B 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 NAS4121-291B?
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 NAS4121-291B?
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.