diff --git a/swh/objstorage/api/client.py b/swh/objstorage/api/client.py
--- a/swh/objstorage/api/client.py
+++ b/swh/objstorage/api/client.py
@@ -8,9 +8,11 @@
 from swh.model import hashutil
 from swh.objstorage.exc import Error, ObjNotFoundError, ObjStorageAPIError
 from swh.objstorage.interface import ObjStorageInterface
-from swh.objstorage.objstorage import DEFAULT_CHUNK_SIZE, DEFAULT_LIMIT
-
-SHA1_SIZE = 20
+from swh.objstorage.objstorage import (
+    DEFAULT_CHUNK_SIZE,
+    DEFAULT_LIMIT,
+    ID_DIGEST_LENGTH,
+)
 
 
 class RemoteObjStorage(RPCClient):
@@ -50,5 +52,5 @@
         if last_obj_id:
             params["last_obj_id"] = hashutil.hash_to_hex(last_obj_id)
         yield from iter_chunks(
-            self._get_stream("content", params=params), chunk_size=SHA1_SIZE
+            self._get_stream("content", params=params), chunk_size=ID_DIGEST_LENGTH
         )
diff --git a/swh/objstorage/backends/pathslicing.py b/swh/objstorage/backends/pathslicing.py
--- a/swh/objstorage/backends/pathslicing.py
+++ b/swh/objstorage/backends/pathslicing.py
@@ -17,7 +17,7 @@
     DEFAULT_CHUNK_SIZE,
     DEFAULT_LIMIT,
     ID_HASH_ALGO,
-    ID_HASH_LENGTH,
+    ID_HEXDIGEST_LENGTH,
     ObjStorage,
     compressors,
     compute_hash,
@@ -74,7 +74,7 @@
             max_char = max(
                 max(bound.start or 0, bound.stop or 0) for bound in self.bounds
             )
-            if ID_HASH_LENGTH < max_char:
+            if ID_HEXDIGEST_LENGTH < max_char:
                 raise ValueError(
                     "Algorithm %s has too short hash for slicing to char %d"
                     % (ID_HASH_ALGO, max_char)
@@ -119,7 +119,7 @@
             a list.
         """
 
-        assert len(hex_obj_id) == ID_HASH_LENGTH
+        assert len(hex_obj_id) == ID_HEXDIGEST_LENGTH
         return [hex_obj_id[bound] for bound in self.bounds]
 
     def __len__(self) -> int:
diff --git a/swh/objstorage/factory.py b/swh/objstorage/factory.py
--- a/swh/objstorage/factory.py
+++ b/swh/objstorage/factory.py
@@ -16,7 +16,7 @@
 from swh.objstorage.backends.winery import WineryObjStorage
 from swh.objstorage.multiplexer import MultiplexerObjStorage, StripingObjStorage
 from swh.objstorage.multiplexer.filter import add_filters
-from swh.objstorage.objstorage import ID_HASH_LENGTH, ObjStorage  # noqa
+from swh.objstorage.objstorage import ID_HEXDIGEST_LENGTH, ObjStorage  # noqa
 
 __all__ = ["get_objstorage", "ObjStorage"]
 
diff --git a/swh/objstorage/objstorage.py b/swh/objstorage/objstorage.py
--- a/swh/objstorage/objstorage.py
+++ b/swh/objstorage/objstorage.py
@@ -15,9 +15,18 @@
 from .exc import ObjNotFoundError
 
 ID_HASH_ALGO = "sha1"
-ID_HASH_LENGTH = 40  # Size in bytes of the hash hexadecimal representation.
-DEFAULT_CHUNK_SIZE = 2 * 1024 * 1024  # Size in bytes of the streaming chunks
+
+ID_HEXDIGEST_LENGTH = 40
+"""Size in bytes of the hash hexadecimal representation."""
+
+ID_DIGEST_LENGTH = 20
+"""Size in bytes of the hash"""
+
+DEFAULT_CHUNK_SIZE = 2 * 1024 * 1024
+"""Size in bytes of the streaming chunks"""
+
 DEFAULT_LIMIT = 10000
+"""Default number of results of ``list_content``."""
 
 
 def compute_hash(content):
diff --git a/swh/objstorage/tests/test_objstorage_pathslicing.py b/swh/objstorage/tests/test_objstorage_pathslicing.py
--- a/swh/objstorage/tests/test_objstorage_pathslicing.py
+++ b/swh/objstorage/tests/test_objstorage_pathslicing.py
@@ -11,7 +11,7 @@
 from swh.model import hashutil
 from swh.objstorage import exc
 from swh.objstorage.factory import get_objstorage
-from swh.objstorage.objstorage import ID_HASH_LENGTH
+from swh.objstorage.objstorage import ID_DIGEST_LENGTH
 
 from .objstorage_testing import ObjStorageTestFixture
 
@@ -86,7 +86,7 @@
             all_ids.append(obj_id)
         all_ids.sort()
 
-        ids = list(self.storage.iter_from(b"\x00" * (ID_HASH_LENGTH // 2)))
+        ids = list(self.storage.iter_from(b"\x00" * ID_DIGEST_LENGTH))
         self.assertEqual(len(ids), len(all_ids))
         self.assertEqual(ids, all_ids)