South Korean memory chip maker Samsung Electronics is facing its worst-ever strike, with nearly 48,000 workers threatening to walk off production lines on Thursday for 18 days over a dispute about bonus payouts. Samsung's union has asked the company to abolish a cap that limits bonuses to 50% of annual salaries and to allocate 15% of annual operating profit to a bonus pool that would be distributed to workers. It also wants Samsung to make the changes binding beyond this year.