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Jeff,

general purpose round-bodied metal film (MF) resistors will often have been trimmed with a spiral, but there are absolutely no guarantees with this. Specialist resistors are usually trimmed longitudinally, and this can be checked with the manufacturer's data sheet. SMD resistors will usually be trimmed longitudinally, but, again, this is not guaranteed. All of this is at the manufacturer's discretion, and for a wide enough tolerance band the manufacturer may simply not bother to trim. The manufacturer may also mark resistors according to a measured value, which is also an option for an end user who selects the required value from a batch.

A resistor will possess, besides the quality of resistance an amount of self-inductance and an amount of self-capacitance. Depending on the frequency of operation, and the accuracy that is required, then one is in to doing sums.

So yes, generic MF or metal oxide (metox) resistors will usually suffer from an excess of self-inductance, as will carbon film resistors. Carbon composition resistors do not, but have very serious problems in the contexts of precision and stability.

When one is concerned with the self-inductance of a ?Watt precision resistor, then the inductance and capacitance of wiring and other components become serious issues.

And all of this is why test gear, and knowing exactly what it is that one is measuring, and to what accuracy, is such fun/jolly hard work/something of a physics experiment (delete as applicable)…

HTH, 73, Stay Safe,

Robin, G8DQX