I thought all 1/4W resistors were the same...

Caedarn

Caedarn

Member
...or at least the same size. I just received some Yageo resistors from Mouser. Two of the values I ordered are much smaller than any other 1/4W resistor I've every purchased. They look like 1/8W resistors. But the Mouser specs say they're 1/4 W.

I'm wondering if there are any possible issues with these that I should be aware of?

Here's a link to one example of what - at least in my experience - is the 'typical' 1/4W resistor:
https://www.mouser.com/ProductDetail/603-MFR-25FRF52-33K
Theses resistors are 2.4mm dia x 6.3mm length.

These 'small' resistors are Yageo MFR-25SFTE series. Here's an example:
https://www.mouser.com/ProductDetail/603-MFR25SFTE26-10K

They are 1.9mm dia x 3.4mm long.

They have a lower Temperature coefficient (50PPM vs 100PPM) and in some cases lower voltage rating (200V vs. 250V) but I don't think these matter.

So these tiny resistors will be fine, right?
 
I have a lot of 1/4 watt 1% metal film in <6mm length.

It's pretty easy to filter search results at Digikey or Mouser to only include those. I notice a lot of boards want the smaller footprint, and they make vero board builds tighter.
 
This is so dumb to say but I’ve ordered some of those in the past and although the tin says one thing, I look at those resistors and think “I don’t trust that.” I suppose I should use some of these!
 
KreoPensas said:
I have a lot of 1/4 watt 1% metal film in <6mm length.

It's pretty easy to filter search results at Digikey or Mouser to only include those. I notice a lot of boards want the smaller footprint, and they make vero
Click to expand...
Yes, for resistors I filter by the product Series, power, and tolerance. It didn't occur to me to filter by size.
 
Filtering by size can be helpful if you're looking for consistency in the way everything looks.

Ratings don't really tell the whole story. Some are larger, some are smaller. Vishay RN55'S are rated for 1/8 watt. CMF55'S are rated for 1/4 watt.

They're the exact same resistor, RNs are mil-spec, CMFs are non-mil spec. Just a little different markings, same damned thing.

Components are fun.
 
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