5.1k ohm 1W 2512 1% SMD RESISTOR

 

If your board needs a 5.1k ohm 1w resistor, and the old part is a 1% 1W chip in a 2512 body, this is the part to order. It is a 5.1k ohm resistor in a large rectangular surface-mount body, built for stable, efficient performance in solar inverters and other power electronics where a steady mid value must hold. It fits voltage division, power regulation, and circuit protection jobs that need a fixed 5.1K value at up to 1W. It does not fit jobs that need a different resistance value, a through-hole body, or more than 1W of power. Check the checks below before you order, so the value, the power, the voltage, and the body all match your board.

This is an original, high-quality part.

What it does

A resistor limits current and drops voltage in a circuit. A chip resistor does that job as a small flat part that solders straight onto the pads of a board, with metal ends that make the contact. This 5.1k ohm 1% resistor holds its 5.1K value within 1%, so a board that calls for 5.1K gets between 5,049 and 5,151 ohm. The 5.1K value is a mid value: it passes far less current than a low-value part at the same voltage, so it fits dividing and biasing work rather than heavy load work, while the big 2512 body sheds heat far better than the smaller 0603 and 1206 parts. The 2512 body is about 6.35 mm long, so it fits boards where a smaller part would run too hot.

Repair techs use a part like this as a 5.1k ohm 2512 resistor for voltage division, where it takes a share of the voltage so the next stage sees the right level, and for power regulation, where a steady mid value keeps a supply stage stable. It also fits circuit protection, where a fixed value sets a safe level for the next stage. You can check the value from the marking: the 4-digit value code for this part is 5101, which reads as 510 followed by one more zero, or 5,100 ohm. The 3-digit code for the same value is 512.

Key features

• 5.1K Ohm fixed resistance, ±1% tolerance
• 1W power rating at 70°C ambient
• Thick film chip construction, surface mount
• 2512 body: about 6.35 mm × 3.10 mm × 0.55 mm
• Maximum working voltage 200V (series limit — the 1W rating caps this value at about 71.4V)
• Temperature coefficient ±100 ppm/°C
• Wide temperature range: −55°C to +155°C
• 4-digit value code 5101; 3-digit code 512

Checks before you order

• Value: your board list must call for 5.1K. A nearby value is not the same part — if your board needs a different value, stop and check the board list again. A 510 ohm part in the same 2512 body is a different value for a different job, not a swap for this one.
• Power and heat: the power this part turns into heat must stay at or below 1W, and that 1W counts only up to 70°C ambient — above that, the safe power drops, so check the derating for your real working temperature. Work out the power from your real voltage and current (power = voltage × current) and keep it inside 1W with room to spare.
• Voltage: the voltage across this part must stay at or below about 71.4V in steady use. At this value the power rating is the real limit: at 200V the part would use about 7.8W, far above its rating, even though 200V is the series voltage limit. Work out the voltage from your circuit before you order.
• Tolerance: the real value may sit up to 1% away from 5.1K. If your circuit needs tighter than 1%, this part is the wrong pick — do not hope the part you get sits near the middle.
• Body and fit: your board must take a 2512 surface-mount body. Measure the old part and match it against the pads and the space on your board. The series body is about 6.35 mm long, 3.10 mm wide, and 0.55 mm high — if your old part is much smaller, check the board list again before you order. A 2K part in the same 2512 body is a different value for a different job, not a swap for this one.
• Fit for the job: if your circuit only needs a fraction of a watt, this part still works. Match the value first, then the power, then the body — a through-hole resistor is the wrong shape for a surface-mount board, even if the value matches.

Specifications

All figures below are from the maker series documents for this chip resistor family. No figure here was guessed. The maker of the exact part on this page is not stated on the live page, so the publisher should confirm the series figures against the Download file at publish time (see the gates note).

Type	Thick film chip resistor, surface mount
Resistance	5.1K Ohm (5,100 Ω)
Tolerance	±1% (5,049 to 5,151 ohm)
Power rating	1W at 70°C
Maximum working voltage	200V (series limit; the 1W rating caps this value at about 71.4V)
Maximum overload voltage	500V
Dielectric withstanding voltage	500V (see the gates note — the second series source gives 300V)
Temperature coefficient	±100 ppm/°C
Operating temperature range	−55°C to +155°C
Marking	4-digit value code 5101; 3-digit code 512 (see the gates note)
Body	6.35±0.10 × 3.10±0.15 × 0.55±0.10 mm
Derating	Full power to 70°C; derate above 70°C

Other names for the same part (good to know)

Shoppers and repair techs call this same part by a few names. 5.1k ohm 1w is the plain name from its value and power. 5.1k ohm resistor is the name buyers use with the unit spelled out. 5.1k ohm 2512 resistor is the name buyers use when the body size matters. SMD resistor is the name for its surface-mount style. 5.1k ohm 1% is the short name that carries the value and the tolerance together. If your board list calls for 5.1K at 1W with 1% tolerance in a 2512 body, this page is the right match. Do not judge by size alone — check the value, the power, and the tolerance too.

Frequently Asked Questions

What does 5.1K mean?

It means 5,100 ohms of resistance. K stands for kilo, which means one thousand, so 5.1K is 5.1 × 1,000 ohms.

What does 1% mean, and what does 1W mean?

1% is the tolerance: the real resistance may sit up to 1% above or below 5.1K, so between 5,049 and 5,151 ohm. 1W is the power rating: the most power the part can turn into heat without damage, rated at 70°C ambient, with less allowed as it gets hotter.

What is the 5101 marking on the body?

It is the 4-digit value code for this part: 510 stands for the digits 510, and the last 1 means one more zero, so 5101 means 5,100 ohm. The 3-digit code for the same value is 512. There is no EIA-96 code for this value, because 5.1K is not an E96 series value.

Can I use this part at 200 V if the power is small?

No. At 5.1K the 1W rating is the limit that matters: it caps the steady voltage at about 71.4V. At 200V this part would use about 7.8W, far above its rating. The 200V figure is the series voltage limit, not a voltage you can use at this value.

How do I fit a 2512 chip resistor?

Solder it onto the matching pads on the board — it has no leads, so it sits flat on the pads. Check the pad spacing against the 6.35 mm body before you solder, use a fine tip and a small amount of solder, and do not overheat the part.

What is the price of this part?

Check the live price on the website. The price shown on the product page is the current one.

Use note kept from the old page: this part was listed before as a 5.1K ohm 1W 2512 SMD resistor, a high-precision component for stable and efficient performance in electronic circuits, including solar inverters, with 1% tolerance for accurate resistance values, in the 2512 package for enhanced power dissipation, reducing heat buildup and long-term stability, ideal for power regulation, voltage division, and circuit protection in high-power environments, built with high-quality materials for durability and minimal deviation from nominal values, surface-mount for compact PCB layouts and assembly efficiency, for solar inverters, industrial power systems, and automation applications, for optimal power management and circuit stability — and that use still stands.