1K Ohm 1/2W 5% Carbon Film Fixed Resistor

 

If your board needs a 1k ohm resistor, and the old part is a 1/2W carbon film part with 5% tolerance, this is the part to order. It is a 1k ohm resistor in an axial through-hole body, built for current control, voltage regulation, and circuit protection where a small 1/4W part would run too hot. It fits inverter maintenance, power supplies, and general circuit jobs that need a fixed 1k value at up to 1/2W. It does not fit jobs that need a different resistance value, a surface-mount body, or more than 1/2W 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 carbon film resistor does that job with a thin carbon layer on a ceramic rod, which gives steady, low-noise performance for standard circuit work. This 1k ohm 1/2W resistor holds its 1k value within 5%, so a board that calls for 1K gets between 950 and 1,050 ohm. The 1/2W rating is what sets it apart from the small 1/4W resistors used for light signal work only — it can turn more electrical power into heat without damage, as long as the cooling and the voltage limits below are respected.

Repair techs use a part like this as a 1k ohm resistor for current control, where it holds current to a safe level, and for voltage regulation, where it takes a share of the voltage so the next stage sees the right level. It also fits circuit protection, where a fixed resistance keeps a fault current inside safe limits. It is an axial resistor, so it mounts through holes on a board, not on the surface.

Key features

• 1K Ohm fixed resistance, ±5% tolerance
• 1/2W power rating at 70°C ambient
• Carbon film construction for steady, low-noise work
• Axial leads for through-hole mounting on PCBs and breadboards
• Maximum working voltage 350V (see the power-based limit in the checks)
• Temperature coefficient −500~+350 ppm/°C
• Wide temperature range: −55°C to +155°C

Checks before you order

• Value: your board list must call for 1K. A nearby value is not the same part — if your board needs a different value, stop and check the board list again. A 1.5K part in the same family is a different job, not a swap for this one.
• Power and heat: the power this part turns into heat must stay at or below 1/2W, and that 1/2W counts only up to 70°C ambient — above that, the safe power drops toward zero at 155°C, 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 1/2W with room to spare.
• Voltage: the voltage across this part must stay inside the limits in the table. From power alone, the working voltage for a 1K part at 1/2W is about 22.4V, and the series cap is 350V — stay below both. Above that, this part is the wrong pick.
• Tolerance: the real value may sit up to 5% away from 1K. If your circuit needs tighter than 5%, this part is the wrong pick — do not hope the part you get sits near the middle.
• Body and fit: your board must take an axial through-hole body. Measure the old part and match it against the holes and the space on your board. The series normal-style body for a 1/2W part is about 9.0 mm long and 3.3 mm across — if your old part is much bigger, check the board list again before you order.
• 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 220 ohm part in the same family is a different value for a different job, not a swap for this one.

Specifications

All figures below are from the maker series documents for this 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	Carbon film fixed resistor, axial leads, through-hole
Resistance	1K Ohm (1,000 Ω)
Tolerance	±5%
Power rating	1/2W at 70°C
Maximum working voltage	350V
Maximum overload voltage	700V
Voltage proof on insulation	500V
Temperature coefficient	−500~+350 ppm/°C
Operating temperature range	−55°C to +155°C
Derating	Full power to 70°C; derate above 70°C to zero at 155°C

Other names for the same part (good to know)

Shoppers and repair techs call this same part by a few names. 1k ohm is the plain name from its value. 1k ohm 1/2W resistor is the name buyers use when the power rating matters. Carbon film resistor is the name for its construction type. Axial resistor is the name for its lead style. 1k ohm 5% is the short name that carries the value and the tolerance together. If your board list calls for 1K at 1/2W with 5% tolerance in an axial 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 1K mean?

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

What does 1/2W mean, and what does 5% mean?

1/2W 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. 5% is the tolerance: the real resistance may sit up to 5% above or below 1K, so between 950 and 1,050 ohm.

Is 1K used for current limiting?

Yes, 1K is a common current-limiting value, where it holds the current through a stage or a load to a safe level. But do not order it for that job on the value alone — check that your circuit also allows a 1/2W axial part with 5% tolerance.

Can I use a different value, like a nearby kilo-ohm part?

No, not without checking the circuit. A resistor value sets the current and the voltage drop, so a different value changes how the circuit behaves. Only swap in a different value if the circuit design allows it — otherwise match the board list exactly.

How do I fit an axial resistor?

Push the two leads through the matching holes on the board, bend them flat on the back if the board needs it, and solder them. Check the spacing of the holes against the body length before you solder, and keep the body clear of parts that cannot take heat.

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 1K ohm resistor for efficient circuit performance in solar inverter repairing and other electronic applications, used for current control, voltage regulation, and circuit protection, with carbon film construction for low noise in sensitive circuits and axial leads for easy mounting on PCBs, breadboards, and custom projects, in inverter maintenance, power supplies, and general circuit applications — and that use still stands.