Remanufactured for HP 45 Black Ink Cartridge (51645A) | Castle Ink

HP 45 Black (51645A) at a glance: a black ink cartridge. Remanufactured: a genuine HP 45 cartridge, cleaned, refilled and print-tested. Fits the HP DeskJet 700C–990C and 1000C–1280, OfficeJet G/K/R series and Photosmart 1000–1315. Backed by a 1-year 100% satisfaction guarantee; orders by 4 PM ET (Mon–Fri) ship the same day from Long Island, NY.

Key Facts

What's in the Box

• 1 × HP 45 Black (51645A) remanufactured ink cartridge

Compatible Printers (38 models)

• HP DeskJet 710C / 720C / 722C / 820C / 830C / 850C / 870C / 880C / 890C / 895C
• HP DeskJet 930C / 932C / 950C / 960C / 970C / 990C
• HP DeskJet 1000C / 1100C / 1120C / 1220C / 1280
• HP DeskJet 6122 / 6127
• HP OfficeJet G55 / G85 / G95 / K60 / K80
• HP OfficeJet R40 / R45 / R60 / R80
• HP Photosmart 1000 / 1100 / 1115 / 1215 / 1218 / 1315

Don't mix these up: HP 45 black pairs with HP 23, 41 or 78 color depending on the printer. It is not the same as HP 15 or HP 40.

Not sure? Look up your exact model on our Find Ink by Printer page, or contact us and we'll confirm the right cartridge for you.

Part Numbers & Also Known As

This cartridge replaces or is also searched for as: 51645A, HP 51645A, HP 45 black, HP45 black, 45 black ink, HP 45, HP45, 51645, 51645D, No. 45, DeskJet 970Cxi ink

Chips, Printer Messages & Installation

Installing: open the cartridge access door and wait for the carriage to move to the center. Press down on the old cartridge to release it and pull it out. Unwrap the new one, pull off the plastic tape by its tab without touching the copper contacts or nozzles, and slide it into its slot at a slight upward angle until it clicks. Close the door and print the alignment page if prompted.

"Cartridge problem" or "incompatible cartridge": remove the cartridge, wipe the copper contacts with a dry lint-free cloth, check that all the tape is off, and reseat it until it clicks.

Streaks or missing colors: run the printhead cleaning from the printer's Tools menu or HP software. The printhead is built into these cartridges, so a cartridge that stays streaky after two cleanings is the likely culprit.

Still stuck? See our guide to fixing a cartridge that isn't recognized or contact us and we'll make it right.

Remanufactured vs. Compatible vs. Original

Original (OEM) cartridges are new from the printer brand and cost the most. Remanufactured cartridges, like this one, start as genuine original shells (including the original chip) that are cleaned, refilled with high-quality ink and print-tested, so they fit and communicate like the original at a fraction of the price. Compatible cartridges are built new by a third party with their own chip. Castle Ink sells remanufactured inkjet cartridges and compatible (newly manufactured) toner.

Other Options for the Same Printers

• HP 45 Black Ink Cartridge (51645A)

Frequently Asked Questions

Will this void my printer warranty?

No. Under the U.S. Magnuson-Moss Warranty Act, a manufacturer can't void your printer warranty just because you used a third-party or remanufactured supply. If a non-original supply directly caused damage, that specific repair might not be covered.

How long can I store it?

Store it sealed, at room temperature and out of direct sunlight, and use it within about 24 months for best results. Once opened, install it promptly.

When will my order ship?

Orders placed by 4 PM ET, Monday through Friday, ship the same business day from Long Island, NY, by USPS (2–5 business days). Expedited 1–2 day delivery is available at checkout, and shipping is free on orders over $50.