any problem with carrying cold steel on bike?
 

I mean long knives, small hatchet etc in panniers when crossing boarder?
I use to travel with some knives usually.

I am travelling with small travel axe. No problems, only once it was taken by Chinese customs (had to buy new one).
If you mean machete, it might cause some issues...

A small travel axe for cutting wood should be OK. Long Knives could be confiscated at border crossings. In Chad they asked me what the axe and small kitchen knife I had on me were for and I said for cutting wood and food. I was allowed to keep them.
They would probably let you keep such items if they were kept together in one place with other stuff like forks, sieve, tea bags, plates, etc. I had the top box as my kitchen.

I find if you are about to be searched carrying any knifes etc.. it's worth being up front. I normally say something like "be careful in that pannier because it contains my cooking knife" or whatever. Often I get OK thanks for letting me know. Never had any issue even carrying a full size chefs knife.

Knives which look like the sort you see on horror-killer-stabbing-murder-movies may well cause a sharp intake of breath and raised eyebrows with even the most friendly border guards.

I carry a 2' long Ghanian "cutlass" (machete to the rest of the world) strapped under my rear bag. Crossed 4 countries and it's only been mentioned once. I say it's for cutting wood and that's that, it's not hidden or anything. I think most rural African's get their first machete at around 8 years old so I didn't think it's that big of a deal.

Africa, carry anything you want. As long as it's smaller than the border guard has.

I understand then this one would be out of the line...

http://sirbikesalot.com/uploads_imag..._machete_2.jpg

carrying cutting tools
 

My experience too. Each country has its own rules, and each borderguard/police has their own interpretation. If your knife, saw, axe looks like a well used tool it should be no problem.
Shiraz in '08 the police did a search on me. They scared me by calling my Sudoku magasine a "numbers code", it was only later I realised they were fooling with me. One older guy had my papers, the younger muscleman was making a thorough search of my gear - sniffing tea, tasting suger, emptying bags and opening everything. They were really "in command" until Mr Muscles pulled my Mora knife out of its sheath - and cut his finger badly. Blood, lots of it. I bandaged him nicely, and and their mood changed to friendlier. They told me to leave Iran as fast as possible as my Pakistani visa expired in three days, and they were not sure of me as a bona fide traveller. It could so easy have gone the other way.
Tools ok - weapons a big no-no, anywhere in the world.

Safe travels

Peter, in Oslo