01R vs 1R0

[Rick Law]

Is there any difference between 01R vs 1R0 on the SMD?  They are both 1ohm according to nomenclature.

I see both on a PC server motherboard.  That led me to think it may not be just different manufacturer as the server-board guy likely purchased the 01R and 1R0 from the same maker.

[tron9000]

give it a test with the ol' DMM

[Monkeh]

I see both on a PC server motherboard.  That led me to think it may not be just different manufacturer as the server-board guy likely purchased the 01R and 1R0 from the same maker.

I'd be willing to bet the P&P (or P&Ps) had multiple reels of 1R. They place A Lot™ of parts.

[Maxlor]

There's a difference in the accuracy of the parts I'd guess?

[TimFox]

Leading zeros are not significant.
Trailing zeros are significant.

[Rick Law]

give it a test with the ol' DMM

With just it expected to be around 1ohm, testing in-circuit is likely not meaningful.  This one looks like an 0603 or smaller on a still-in-used motherboard.  It is easy to loose something that small when removed.  I have yet to find a 0805 green LED that I knew for sure felt off the table and by now probably in LED heaven.

These days, I scotch-tape SMDs down on the table top and only remove it from the scotch-tape covering when I am fully ready to solder that specific SMD.

Leading zeros are not significant.
Trailing zeros are significant.

This is a good thought.
 * 01R is 1ohm with 1-digit accuracy.
 * 1R0 is 1.0 ohm with 2-digit accuracy.
Unless/until another reason pops up, I will take it as 1 or 2 digit accuracy, I suppose.  But I am still uncomfortable with that since accuracy is typically specified as 1% 5%...  This is too esoteric even for my curiosity.

[fivefish]

Who still uses 5% resistors?  It's not the 80s anymore, 1% can be bought for $5.00 for 200pcs. They're so cheap nowadays.

I only use 1% or better now in all my projects except if a value is OUT OF STOCK and I just want to get the project going, then I'll buy the 5%.

[Rick Law]

Who still uses 5% resistors?  It's not the 80s anymore, 1% can be bought for $5.00 for 200pcs. They're so cheap nowadays.

I only use 1% or better now in all my projects except if a value is OUT OF STOCK and I just want to get the project going, then I'll buy the 5%.

re: "Who still uses 5% resistors?"

Yeah, I agree with what you said.  Failing to find any difference between 1R0 vs 01R, I consider 1 ohm vs 1.0 ohm as a plausible explanation for now.

I see both on a PC server motherboard.  That led me to think it may not be just different manufacturer as the server-board guy likely purchased the 01R and 1R0 from the same maker.

I'd be willing to bet the P&P (or P&Ps) had multiple reels of 1R. They place A Lot™ of parts.

This is also a very likely explaination in my mind.  It could be just manufacturers labeling identical stuff differently.  As Monkeh suggested, it could be there was a wheel change between R5 and R36 (I am making the resister number up, I am not going to re-open the server just to re-read the resister number printed on the PCB).

[m98]

Who still uses 5% resistors?  It's not the 80s anymore, 1% can be bought for $5.00 for 200pcs. They're so cheap nowadays.

Even in high-end products you won't waste money on not needed accuracy. Why would you waste more than one cent per resistor just to have for example an 1% accurate pull-up?

[fivefish]

Who still uses 5% resistors?  It's not the 80s anymore, 1% can be bought for $5.00 for 200pcs. They're so cheap nowadays.

Even in high-end products you won't waste money on not needed accuracy. Why would you waste more than one cent per resistor just to have for example an 1% accurate pull-up?

And I don't think manufacturers would waste an entire PNP feeder to load a 5% resistor just to save one cent for a pull-up resistor using your example, they'll just use other existing resistor values, even if it's 1%.

In the same way that re-using resistor values rather than waste an entire feeder to load a different value... i.e. just load a single 10K reel on the feeder, and design the board to use (2) 10K resistors in parallel, rather than using a separate 10K and 5K reel of resistors. 

[logictom]

Who still uses 5% resistors?  It's not the 80s anymore, 1% can be bought for $5.00 for 200pcs. They're so cheap nowadays.

Even in high-end products you won't waste money on not needed accuracy. Why would you waste more than one cent per resistor just to have for example an 1% accurate pull-up?

And I don't think manufacturers would waste an entire PNP feeder to load a 5% resistor just to save one cent for a pull-up resistor using your example, they'll just use other existing resistor values, even if it's 1%.

In the same way that re-using resistor values rather than waste an entire feeder to load a different value... i.e. just load a single 10K reel on the feeder, and design the board to use (2) 10K resistors in parallel, rather than using a separate 10K and 5K reel of resistors.

Surely this is a toss up between how many reels are required for the run therefore how many runs through a pick'n'place vs the cost of adding two parts rather than one, board space taken up, number of boards run, etc, etc - it comes down to design/manufacturer specifics.
I guess there's rules of thumb but how could you generalise it one way or the other?

[m98]

Who still uses 5% resistors?  It's not the 80s anymore, 1% can be bought for $5.00 for 200pcs. They're so cheap nowadays.

Even in high-end products you won't waste money on not needed accuracy. Why would you waste more than one cent per resistor just to have for example an 1% accurate pull-up?

And I don't think manufacturers would waste an entire PNP feeder to load a 5% resistor just to save one cent for a pull-up resistor using your example, they'll just use other existing resistor values, even if it's 1%.

In the same way that re-using resistor values rather than waste an entire feeder to load a different value... i.e. just load a single 10K reel on the feeder, and design the board to use (2) 10K resistors in parallel, rather than using a separate 10K and 5K reel of resistors.

Sure, that depends on the application. But often you won't need any 1% resistors in a (digital) circuit.

[SeanB]

Sure, that depends on the application. But often you won't need any 1% resistors in a (digital) circuit.

True, but the manufacturer might already have the part in a feeder on the machine for another job, so it makes sense to simply use it as it meets the required spec. The particular board might only be a small run in amongst a larger run of boards, so minimising the number of feeder changes between jobs is a good thing to save wear on them, plus the cost difference between the parts might be zero. You often design a board and component layout based on a particular manufacturer's standard part feeder list, so that you do not pay a rereeling fee to have a part placed in a feeder just for you.