By Rabbi Dovid Ostroff
Is one permitted to use a hammer to crack open a nut?
This brings us to the next muktze category called k’li she’mlachto l’issur. A k’li she’mlachto l’issur is defined as a k’li generally used for actions that are prohibited to be done on Shabbos. A hammer, for example is used for hammering nails into wood, which involves an issur either of Boneh – Construction, or of Makeh B’patish – Applying the Finishing Touch.
The halacha applicable to this category is that if the k’li is needed (for something permissible – of course), it may be used. The term used is l’tsorech gufo – for use of itself. Therefore, if one needs the hammer to crack open nuts, one may use it. If a screwdriver is needed to pry open a jammed lid, one may.
Before one wishes to use a k’li, one must be sure that the particular k’li belongs in this category of muktze. As we learned in the previous sheet, a k’li that is muktze machmas chisaron kis may not be used l’tsorech gufo, as it is totally muktze.
If I have a nutcracker, may I nevertheless use a hammer?
The Mishna Berura says 1 that one may only use a k’li she’mlachto l’issur when no other k’li is available. Accordingly, if you have a nutcracker, you should not use a hammer. If a knife will pry open the jar, do not use a screwdriver.
This appears to be a matter of availability. If your neighbor has a nutcracker, you would not be required to borrow it from him, and you may use the hammer. If however, the nutcracker requires a little searching for, it is debatable.
If a screwdriver is occupying my chair, may I remove it?
Another application of this category is that if a k’li she’mlachto l’issur is occupying space needed for one’s use, it may be moved. If a writing pen, for example, is on a chair needed for sitting on, it may be relocated.
Once it is removed from the chair and is still in my hands, may it be placed where it belongs or must it be put down as soon as possible?
The Shulchan Aruch rules 2 that the item may be placed wherever the person wants to put it.
If one lifted a muktze item when he was not allowed to, must it be put down as soon as possible, or once it is already in one’s hand, it may be put wherever he wants?
This question can be divided into two parts. 1) Does this permit apply to sticks and stones as well (other muktze categories)? 2) If a k’li she’mlachto l’issur was accidentally picked up, may one continue with it to wherever he wants?
The Magen Avraham 3 holds that this is a general permit for all muktze items. I.e. if a muktze item was lifted, it may be placed anywhere. The M”B 4 however, says that the poskim disagree and ruled that this leniency applies solely to the category of keilim shem’lachtam l’issur. In other words, if an expensive camera was unintentionally picked up, it must be put down immediately. If one lifted a stone and remembered that there is no heter to move it at all, it must be dropped there and then.
As for the second issue, the Vilna Ga’on holds that the heter of placing items wherever one chooses applies only if the item was lifted up when it was permitted to do so. If, however, a k’li she’mlachto l’issur was lifted absentmindedly, or when there was no heter to do so, it must be put down there and then.
 Simon 308:12.
 Simon 308:3.
 See Sha’ar Ha’tsiun 308:14.
 Simon 308:13.