Master Lock · Electronic Components
491B
Locking Device, Circuit Breaker
Part Number491B
ManufacturerMaster Lock
AvailabilityAvailable to order — request a quote
Specifications
NSN5925-01-570-3236 (NSN)
Federal Item NameLOCKING DEVICE,CIRCUIT BREAKER
Federal Supply Class5925 — Circuit Breakers
MaterialSTEEL
Vendor Part Numbers0652 3349
ESD/EMICode A — ESD/EMI sensitive item
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 491B available?
We can source 491B 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 491B by Master Lock obsolete or end-of-life?
We specialize in obsolete, end-of-life, and discontinued components. If 491B 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 491B?
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 491B?
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.