Avoid numerical criteria in Keyword search. For specific item numbers, try the Part Number search. For product specifications, try the Search Items feature available throughout the catalog.
Use fewer keywords or part numbers. Try fewer keywords or part numbers to start with and then build on your initial results by adding more.
Make your search more general. For example, instead of using specific part numbers, try using the generic product category.
Check your spelling. Are the words in your query spelled correctly?
Try using synonyms/abbreviations. Maybe the product you are looking for uses slightly different words, like "cm" instead of "centimeters".
Avoid special characters. Characters such as @, #, ^, % often produce zero results.