Difference in a Jigmaster and a Senator?

[Alto Mare]

Ken,  you got good information above.
Basically all are the same with a few differences.
As already mentioned, the Senator series come with reinforced rings as the jigmasters don't.
This makes them a little stronger when compared to the same size.
If  fished at where they were intended to be fished at, you wouldn't go wrong with either.

I'm assuming you meant stock reels.

Now, just in case you're talking upgraded  reels, the Jigmaster with the following:
Cortez Conversion plates
Tiburon frame
Pro Challenger stainless steel guts, including the latest HX gears
Motive Fabrication handle arm

is on a league of its own.

A well equipped Jigmaster is a much stronger reel when compared to a Senator of the same size and very hard to beat, but it isn't cheap.

Here are the specs on stock Jigmasters:
http://www.pennfishing.com/penn-reels-conventional-reels-penn-jigmaster/penn-jigmaster-star-drag/1285653.html#start=1
There isn't anything wrong with these as they are, we just made them a tad stronger .

As I'm mentioned on previous posts, our upgraded Jigmasters could be pushed to 20lb max with no issues.
I can't wait to see what these little reels could do.

Sal

[basto]

The reinforced rings are not the only thing stronger on the black 3/0. It also has more frame pillars and more screws in the stand.
I also think the way the head plate is attached to the frame is a stronger method than the Jigmasters quick takedown.
Comparing stock to stock.
Basto

[Alto Mare]

You are correct Basto.
I know my Senators very well and don't mean the ones at Washington DC  , I just didn't go into all the details.
There has also been talks that the right side plate on the Jigmaster blows up at times, I've been fishing these easy take apart reels for some time now, I can't say it has ever happened to me.

I did see however blown right side plate on the 4/0 and 6/0, I might still have the damaged plates in a box somewhere, those were not mine.
I've also seen cracked right side plate on a 10/0 and on a 16/0, that they were trying to sell on line at a discount.
Maybe user's fault

So, answering Ken's question above, a stock Jigmaster is not stronger than a Senator

Sal