I was using 4lb test on my travel spinning combo but It was too weak for some situation. So the only other line I had was 8lb test, And to my surprise I saw the line rating was 10 to 17lb

Now the question is when they use line rating, It is about the thickness of the line or actual line test? I am almost sure that 8lb test will be really match my rod and the way I am fishing it. Here is the pictures to see all the info.

Super weird I'd never throw 10+ lb nylon on spinning except on my Size 6000 sw spinning reel and super heavy rod

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

G. Loomis inshore MH spinning rods have similar lines ratings.

My advice use whatever line works for you, meaning you can cast the line with ease using the lures you fish with.

Tom

I would say it’s the strength of the line and not the line’s thickness as a best guess. 
 

My reasoning is that a typical braid of 20# test has a mono equivalent diameter of about 6#, and that’s pretty thin. Mono at 20# strength is going to be much thicker by nature of the line’s properties. 
 

Let’s say a rod has a line rating of 12-25#. The rod should in theory handle both the 20# braid and 20# mono quite well and diameter imho does not appear to be a factor. 

Line ratings on reels are only for capacity measurements and line ratings on rods are next to useless. Fish, cover, bait are your concerns for line choices 

I was about say the reel had a really good line lay result for that length of thin line, then I saw it was a Stella.  

 

The spool says 140 yds of 8-lb mono

4-lb test is 0.165 mm diameter, so the capacity is 320 yds of 4-lb test.  

https://www.pattayafishing.net/fishing-reel-line-capacity-estimator/

 

The 150-m capacity is PE#2.5, which is 50-lb braid.  

I hope this thing is on.  

 

You don't tell us what frame size Shimano, but a Yumeya 1215 spool would have the 4-lb capacity you're looking for