The Shechitah Knife

What Can Be Used for Shechitah

1. Technically, anything that is detached from the ground and sharp can be used for kosher slaughter, as long as it's free of imperfections. A reed membrane would be good if it doesn't have any splinters that would come out. Practically, however, this is exclusively done with a knife.
2. One shouldn't use a scythe or even a double edged knife if one side of it is a scythe. Bediavad if he did it and knows he used the kosher side, it's ok, and if he smoothened out the scythe side then he can use it lechatechilah.

Detached From Its Source

1. Anything sharp attached to the ground or a body may not be used for shechitah until it is detached.
2. If it was detached and then reattached, one still should not use it regardless of whether he plans to leave it there (which would render the meat prohibited due to the Gemara's uncertainty) or not (which would be invalid on a rabbinic level). If one's intention is unformulated, we can determine based on context.
3. An animal's jaw with sharp teeth may not be used, as the gaps between teeth are the same as nicks in a knife, but a singly tooth attached to a jaw is fine. Even a single nail on a severed foot would be ok. Some argue that if it's still attached to a whole limb, such as a whole jaw or whole animal foot, that would be considered "attached" to its source of growth.

Pegimot

1. A knife with a pegima (nick) may not be used. Bediavad, if one used it and claims he didn't use that part of the blade, the meat is kosher, but if he didn't realize it was there until afterwards, he has no claim.
2. Ideally even if one covers the pegimah, he might accidentally use the part with the pegimah.
3. If the blade has two edges, one must make sure both are free of pegimot.
4. On Yom Tov or in pressing circumstances, one can cover the pegima and shecht carefully, avoiding the pegimah, as long as there are two neck widths of length left of the knife from the pegimah in either direction and one shechts in a sawing motion. Some say the length is measured from the end of the cloth and not the pegimah. All this applies for two pegimot with enough blade length in between, as well.

Glowing Hot Knife

1. A knife that is heated till it glows (incandescent) may not be used, as the heat from the sides of the blade burns the simanim before the blade finishes severing them, resulting in a piercing instead of a shechitah. The meat would be prohibited on a Torah level. Some are lenient bediavad if the shochet was aware and maneuvered the knife in a way that avoids the sides touching the simanim, but the halacha follows the strict view. Some say the minimum temperature of the metal is Yad Soledet Bo.

Crafting a Shechitah Knife

Modern day shechitah knives are commonly rectangularly shaped to facilitate shechitah without issues of chaladah and derasa and made with easy to sharpen steel that maintains its edge to minimize pegimot.

Chalef with Blue Bone Handle, image courtesy of Laevi Sussman, JewishKnives.com

1. One should use a knife that ends in a right angle, not a sharp point, in order to avoid chaladah. In pressing circumstances, can can cover the tip with something light and then shecht (a hard tip cover could lead to derasa).
2. Some say the top of the knife should also be void of pegimot, in case one ends up cutting with the top, while others note how the rectangular knives we use today avoid this issue.
3. The ideal shechitah knife is twice as long as the neck of the target category; therefore, bird (ofos) knives are usually about five inches long, sheep (dakos) knives are usually nine inches long, and cattle (gasos) knives are usually about sixteen inches long.
4. The instrument used to shecht should preferably be as smooth as possible on both sides. Therefore, although engravings in the blade far from the edge do not render the shechitah invalid, but one should ideally use a knife free of any engravings. Anything sticking out of the side would be a problem even bediavad despite being far from the edge.

Stainless Steel Chalefim in Select Sizes, image courtesy of Laevi Sussman, JewishKnives.com

Sharpening a Shechitah Knife

Sharpening a knife is done by grinding the edge against coarse and then fine whetstones, back and forth, one side and then the other, until the knife is sharp and smooth.

Guides

• Esek Hashechita by Rabbi Dovid Shaffier. See SeforimChatter Review here. (Book)
• Laevi Sussman's Video Guide (Video)
• IBC Experiential Halacha: Basics of Shechita-Knife Sharpening (Audio)
• Guide to Sharpening a Shechita Knife by Rabbi Avraham Moshe (PDF)

Purchasing a Knife

• The Kosher Cut
• JewishKnives.com (Laevi Sussman)
• Lublinsky

Sources

Category	Topics
General Laws of Kashrut	Bishul Akum - Checking for Bugs - Gelatin - Kosher Food without Kosher Supervision - Kosher Food Packaging for Deliveries - Kosher Food Left with a Non-Jew - Koshering a Kitchen - Kashering for Pesach - Kosher in the Workplace - Medications - Pat Palter - Selling Non-Kosher Foods - Serving Guests - Sharp Foods - Shechitah (Kosher Slaughter) - Tevilat Keilim - Tzaar Baalei Chayim - Yashan
Meat and Milk	Dairy Bread - Eating Dairy and Meat at the Same Table - Kosher Cheese - Kosher Milk (Chalav Yisrael) - Milk and Meat in the Kitchen - Non-Dairy Milk - Waiting between Meat and Milk
Principles of Kashrut	Items That Cannot Be Nullified - Transferring Taste - Nullification - Zeh Vzeh Gorem - Trusting Others for Kashrut
Shechitah	Shechitah_(Kosher_Slaughter) - Who_Can_Be_a_Shochet - The_Shechitah_Knife - Modern_Day_Industrial_Shechitah - Glatt Kosher Meat - Kashering Meat